I know I know.. more gas mileage concerns.. I've been following the forums for a while now.. I've got roughly 500miles on the car..
and for the 2 and a hlf tanks of gas I've used.. I am getting 200miles to the TANK! I just received the Road and Track on the 8 and they est a 280mile to the tank. Is anybody getting the same gas mileage??

- Driviing habits - Keeping the RPMS below 5 grand! - Few spurts to 7.. and thats it. - Using 92/93 octane also - Short highway trips (10miles) to work and to school and back.

I've read the other posts, but have not heard nor seen anybody posting how many ACTUAL miles they are getting to the tank, I know its a "sports car" and whatever else ppl have said. To me, for 13 mpg I should be driving a Viper.

My driving habits seem similar to yours and on my second fillup I drove 231 miles before the low fuel light came on, averaging about 17.5 mpg...

yea im getting around 13 mpg around the city. i can actually see the fuel needle going down when im driving from point A to point B.

The worst mileage that I've seen so far, in 2700 miles, has been 12.8 MPG and that was all highly spirited driving. I routinely see 18 MPG with my normal mix of city/highway driving with a moderately heavy right foot.

Am I driving wrong?? Or is there another issue here?? Could the gas station of choice be a problem?

Are you idling the engine a lot (e.g. on cold start)? That seems to burn a lot more in a rotary than in a piston engine, also short trips seems more fuel consuming . Those are the main contributers to my fuel consumtion. AC-headlights-stereo makes only marginal difference.

/Elak

the gas really sucks. I am filling up every other day. I don't drive too hard. I think I'm getting 14 or 15 mpg. This is the only problem I have with the 8. I LOVE THIS CAR

actually on cold start *as cold as its gonna get in Florida* I'm doing like the booklett states/ keep at 3k etc.. / It just seems like the car is EATING the gas..like it has a hole in its mouth.. Just wondering if there is a "problem" in the gas department *excuse me* in the car

Alas, your experience is the same as mine. I've also watched the mileage poll thread - We seem to be at the bottom of the curve for mileage.

I can not get 200+ miles from a tank. On the first tank I got 15.1, then 14.5, then 13.2! I have not pushed the engine hard - never above 6k to date. Most of the driving is 20 miles each way home to work on the freeway.

What's weird is that for the first tank, the average RPM was higher than the last tanks - yet the mileage is dropping. I am very concerned about not only the lousy milage but also the trend of getting worse each tank. Note that each tank has been the same premium gas brand (I'm trying to keep the variables to a minimum while I figure out what the issue is).

This is the only serious thing I have to complain about the car (now complaining about the dealer is another matter entirely).

I talked to Mazda cust service earlier this week (as a result of my latest dealer experience) and asked what could be done - they suggested that I have the dealer "run a fuel consumption test" - so I plan to have that done (what ever that is - hopefully it is something other than having a mechanic put 200 miles on the car :( ) - just as soon as I find a dealer that I think knows anything about a rotary engine...

This week I've been driving like it was an electric car - all shifts between 2k & 3.5k - any lower and the car might as well not be moving. I've also refused to run the air conditioner - with all this I am at about 175 at 1/4 tank... Ok that's better but overall I think this is situation is crap. I'm doing freeway driving - 13mpg is 72% of the city estimate and only 46% of the highway estimate. That is outside reasonable tolerance for an EPA estimate IMHO.

The car is either going to get better or I will seriously start considering the details of forcing a return of the car (which I know will be a huge hassle - hence my careful record keeping and the motivation behind identifying the issue to Mazda USA early).

Frankly, this is a much bigger issue to me than the HP stuff from other threads.

At < 200 per tank, as much as I like the car, it is simply not very practical as a daily driver car.

Hell, If I really want to burn fuel, I go run my boat around (at least a full load there gets me 1000+ miles of fun - even if a full load is 450 gallons - at least I'm moving 30k lbs while using the fuel). :D

Dave

Please don't flame me over this comment, but are you guys sure you aren't driving down the interstate in 4th or 5th not 6th? I've done it (for a short time) cause it really doesn't make much of a different noise and I was paying attention to smthg else at the time (like heavy traffic).

I'm having fun flooring it regularly, certainly not babying it, and I've got 17.5, 18.5, 18.3 three tanks so far... so like 235-250 miles a tank no problem. If I really paid attention, and took a trip (which i haven't done yet), seems like 20+ shouldn't be a problem.

Originally posted by MVCalypso
.
Hell, If I really want to burn fuel, I go run my boat around (at least a full load there gets me 1000+ miles of fun - even if a full load is 450 gallons - at least I'm moving 30k lbs while using the fuel). :D
Dave
Dang, that's one heck of a boat! 3 miles to the gallon, does it have a Rotary too :D

I was seeing about 200 miles per tank the first fillup. Second one half a tank went in 100 miles, but then I started to shift usig the guide in the user manual (about 3KRPM per shift) and cruising about 80MPH, I have gotten an astonishing 200 miles from the rest of the tank. This was all highway driving though with about 40 minutes very light crosstown traffic. Car isnt as fun this way, but mileage is way better. Got 540 miles on the car so far.

Edit: Forgot to mention that I was running AC a lot the first tanks icne it was raining here all the time and with the warm air, it gets real humid, real fast. Last few days have been nice so barely any AC usage, mainly for defogging.

If my next fillup actually runs me for 400 miles, I will be MOST pleased :D This weekend my driving will be light traffic and some highway so it will be a best case scenario. Tank after that I will try to stick to heavy traffic. Visit my clients in downtown Miami and see how that goes. I probably wont be able to arrange enough visits to make it all traffic driving, but if I time the drive home right I will hit rush hour and thats just as good.

13 mpg is way too low. Shoot, even my 25 year old 4bbl carburated 12A rotary gets 16 mpg in the city and 26 mpg on the highway @ 75mph. That's with an antiquated ignition system and me laying on the gas all the time. You guys need to take the car to the dealer and have them figure it out. Idling is where the Renesis is supposed to mop the floor with previous rotaries in terms of fuel consumption.

Just to add insult to injury, there is a guy on the rx7club.com board who has a bridgeported 12A and still got just over 20 mpg on the highway.

Something ain't right here folks. Personally, I think the piss-poor gas mileage and the missing 20 horses are closely linked.

On my drive from Ft. Lauderdale back to Buffalo (after break-in) I did notice steadily increasing mileage and my last tankful took me 289 miles at which time the fuel light came on for about 4 miles before I filled up. Granted, this was 98% highway, but still gave me ~23 MPG (12.6 gal - which I find strange that the fuel warning light comes on sooner than expected - well before hitting E on gauge. I thought it comes on after about 14 gal. leaving 2 spare after warning.) Just some food for thought. Since then i seem to be getting about 230mi/ 12 gal = 19MPG of mostly city (suburb) driving.

Originally posted by TJRX8

Dang, that's one heck of a boat! 3 miles to the gallon, does it have a Rotary too :D

Well, I like it! It's a 36 ft trawler (Island Gyspy 36 Europa for those into boats), displacement about 30k lbs, powered by twin Ford/Lehman 135HP inline 6 diesels. Total of 270 HP...

A single Rotaries would be MUCH smaller (but a performance disaster as low RPM torgue really counts when driving a prop).

Now ya got me wondering - is there any such animal as a diesel Rotary? :eek:

Dave

Originally posted by Spin9k
Please don't flame me over this comment, but are you guys sure you aren't driving down the interstate in 4th or 5th not 6th? I've done it (for a short time) cause it really doesn't make much of a different noise and I was paying attention to smthg else at the time (like heavy traffic).

I'm having fun flooring it regularly, certainly not babying it, and I've got 17.5, 18.5, 18.3 three tanks so far... so like 235-250 miles a tank no problem. If I really paid attention, and took a trip (which i haven't done yet), seems like 20+ shouldn't be a problem.

No flame from me -
yep, I am sure of the gears being used (at least since the first tank) as I've been paying attention to see what I can get from the car - and it just keeps getting worse... I'm frankly puzzled - I read the other posts about 20+ and wonder if we're all talking about the same car.

Dave

I'm on my 3rd fill up and approaching 600 miles on the car. The first tank was great, I recorded 23mpg. The second tank was a whopping 16mpg. I can tell this third tank isnt going to do very well either. For reference I am driving the same route with the same conservative driving style( still breaking it in - can't wait to floor it :). The ironic thing is my TII regulary posted between 20-24 driving the same route.

I find it very uncommon that some are getting good mileage and others are not.. The first half of this tank my shifts have been no greater than 4 grand and I am still at 100 miles (roughly).. So I figure I might as well drive hard once I talk to my dealer.. Not to mention the service tech at the Mazda I bought it from *Fairbanks in Longwood- Is 2nd place in the US/ not too shabby. but with all consideration, will continue to monitor the rest of this tank, and will be contacting Mazda shortly! Thank you for your replies! Helps to know others are getting the same, could use for backup if need be! Will post what the results are.

Joe

wrong button

Originally posted by 8thSin
- Driviing habits - Keeping the RPMS below 5 grand! - Few spurts to 7.. and thats it. - Using 92/93 octane also - Short highway trips (10miles) to work and to school and back.

I've read the other posts, but have not heard nor seen anybody posting how many ACTUAL miles they are getting to the tank, I know its a "sports car" and whatever else ppl have said. To me, for 13 mpg I should be driving a Viper.

8th, my driving habits sound just about like yours. I'm getting between 15.5-17 mpg for the past several tankfuls. I was disappointed at that, but just finally decided to not worry and enjoy the car. At 13 mpg I'd be real upset. It's strange how all our different cars are showing such variance.

I guess I gotta read the owners manual. Does it really say to shift at 3000 rpm? I shift a little higher, 3500-4000. It's just starting to get into its torque band about there, so at 3000 and below you're feeling very little power and the car isn't any fun at all. If that's how they estimate their EPA mileage I'll never get there.

Originally posted by MVCalypso
yep, I am sure of the gears being used (at least since the first tank) as I've been paying attention to see what I can get from the car - and it just keeps getting worse... I'm frankly puzzled - I read the other posts about 20+ and wonder if we're all talking about the same car.
Dave
I have to agree that my mpg is getting worse not better. But I have to concede I drive this car like I would drive any other. I can't drive like an old granny, but even so the best i've ever recorded was 17.25mpg and hit the mid 12's a couple times.. I have averaged 14.5mpg over the course of 1200 miles.. pretty shitty I suppose.

I'm averaging between 25-26 MPG in the EVO. :p

My fuel mileages are actually improving. After 9 fillups and 1770 miles, my fuel consumption is 18.8 mpg. On first tank I drove conservatively and got 16.3 mpg. That was the worst one. It has since increase steadily and has been as high as 20.9 mpg. After 600 miles, I'm shifting around 5k rpm and I'm not holding back in my driving. Even on the last fillup when I had a dozen WOT acceleration runs and pegging the rev limiter, the mileage was only 17.6 mpg. So it's strange that some of your mileage are getting worse.

Originally posted by Good Duck
... On first tank I drove conservatively and got 16.3 mpg. That was the worst one. It has since increase steadily ....
I must drive like a maniac and not realize considering the sizeable difference in mileage. Hmm.. It just seems strange to always have in back of your mind to "manage your revs", drive slow etc..

Oh and I did, in my estimation, kept it easy the first 700 miles of driving, but afterward I been driving as normal (what ever that might mean). I will look at my average up to 700miles and then after. I'm hoping that reports of improved mileage as the car settles in and possible ECU remapping becomes true at some down the road. Happy driving all!

Originally posted by Good Duck
My fuel mileages are actually improving. After 9 fillups and 1770 miles, my fuel consumption is 18.8 mpg. On first tank I drove conservatively and got 16.3 mpg. That was the worst one. It has since increase steadily and has been as high as 20.9 mpg. After 600 miles, I'm shifting around 5k rpm and I'm not holding back in my driving. Even on the last fillup when I had a dozen WOT acceleration runs and pegging the rev limiter, the mileage was only 17.6 mpg. So it's strange that some of your mileage are getting worse.


My mileages are improving just like Good Duck, almost exactly the same numbers. From first tank about 16 mpg to now 19 mpg. I have 1400 miles on my car.

Mine also.... first tank for me was around 15mpg, and it's grown since then. I neared 18mpg last fillup. I think I'll break 20 eventually, but given I do *all* city driving... it's a tough task to accomplish.

Well here is our MPG so far, as reported by my wife. Car has 417 miles on it.

1st Fill up - not documented

2nd Fill up - 20.0 MPG - This is all city driving (Tampa). Wife has NEVER taken the car over 4500 RPM's.

Outstanding MPG for city driving. Better then the reported EPA. So to all the doubting Thomas's, this definately tells us that if you keep your foot off the gas (<4500 RPM's), and drive conservatively, you can at least meet the EPA. But of course you are missing out of some of the fun of taking this baby into the upper RPM's. :D

She'll be traveling to Ft. Myers, and back, this weekend (120 miles one-way) and this will be all highway mileage. I will report back when she fills back up after her trip.

Originally posted by RX-8 Zoomster
... Wife has NEVER taken the car over 4500 RPM's.

So she says... :D


She'll be traveling to Ft. Myers, and back, this weekend (120 miles one-way) and this will be all highway mileage. I will report back when she fills back up after her trip.

Mark,
Make sure to remind her not to stay at a steady speed/RPM for any extended period. At least until the break in is over. In other words no setting the cruise to 95 and kicking back in the leather recliner :)

An update - I just filled the tank again - this time I got 14.4 MPG - this from "granny driving" (and not the type from Pasadena for those old enough to remember Jan and Dean) and not using the air conditioner.

The extra mileage is not worth it to be hot and sticky. I'm sure hoping that it starts improving (I have about 650 on the car now).

Talked to the dealer about the "fuel consumption test" today = he's checking into whether his mechanics know what that is and how to tdo it - at least he was up front about their level of rotary expertise.

Dave

Just under 1k after 5 weeks. My commute is short and I have not taken any trips over 60 miles. I now document my fuel usage after taking note of the 8's hearty thirst. 14 -15.5 and 16 are my MPG results so far.
I love the performance and feel of the car but I sure wish it didn't drink so much!
Maybe a 1000 mile tune-up will lean it out. I doubt it.
TDS

1200+ miles and 15.6 mpg on the last tank of combined driving.

Originally posted by TJRX8


So she says... :D




Funny stuff. I trust her. She knows I'm pretty adamant (bitchy) about "my" car and how I want it treated during the break-in period. When it was time to shift, she used the tac and did not rely on feel or sound. She's one of the best female drivers on a manual transmission I have seen.



Originally posted by TJRX8






Mark,
Make sure to remind her not to stay at a steady speed/RPM for any extended period. At least until the break in is over. In other words no setting the cruise to 95 and kicking back in the leather recliner :)

Tom,

Thanks for the advice, but she knows since I told her earlier. Before the first fill-up (which she didn't document) she had about 50/50 city/hwy driving. When she took it up north to our relatives in Bushnell, on I-75 she didn't use the cruise at all, and varied the mph about every 10 minutes of so.

I real curious to find out what the MPG will be after her trip to Ft Myers. It should be about 15/85 city/highway. I told her to fill-up immediately after her trip, so we can get a better idea of the hwy MPG.

Correct me if i'm wrong, but there was a whole other thread about this which came to the consensus that a rotary (or any engine at that) will get its best mpg at the rpms at which the engine is running most efficiently, and on a rotary this is about 6000, which might explain why some of the granny-type driving during break-in would yield low mpg. I however have never yet bothered to calculate the mpg on my car.

Originally posted by bassik277
Correct me if i'm wrong, but there was a whole other thread about this which came to the consensus that a rotary (or any engine at that) will get its best mpg at the rpms at which the engine is running most efficiently, and on a rotary this is about 6000, which might explain why some of the granny-type driving during break-in would yield low mpg. I however have never yet bothered to calculate the mpg on my car.

wtf 6000??? no way. i would imagin keeping the car at 6000 all the time, would yield even worse gas mileage

Originally posted by tribal azn2


wtf 6000??? no way. i would imagin keeping the car at 6000 all the time, would yield even worse gas mileage

Exactly. MPG's will be lower. If you are keeping the car at a constant 6000 RPM's, you need to upshift son.

This wouldn't apply to overall mileage averages, but I noticed in my RX-8 that sometimes the gas pump nozzle auto-shutoff activates well before the tank is full. I know you're never supposed to completely top off the tank, but I tried last time just to see, and I got 3 more gallons in. If you have one "fill-up" showing unusually low mileage, this could do it.

I'm consistantly getting 19+/mpg after 5 tankfulls. 80% city driving in stop and go in L.A. traffic. During the break-in period I never exceeded 4.5k rpms. Now I rev to 6-7 all the time occasionally hitting 9+k.

I'm taking a road trip this weekend. We'll see what kind of hwy only mpg I'll get.

Originally posted by bobm
This wouldn't apply to overall mileage averages, but I noticed in my RX-8 that sometimes the gas pump nozzle auto-shutoff activates well before the tank is full. I know you're never supposed to completely top off the tank, but I tried last time just to see, and I got 3 more gallons in.I have exactly the opposite experience - when the nozzle clicks off in my car, I can't squeeze another dime's-worth in there.

Originally posted by eccles
I have exactly the opposite experience - when the nozzle clicks off in my car, I can't squeeze another dime's-worth in there.

I have this station I ALWAYS fill up at, and am very familiar with which nozzles I like, etc.

Even parking the 8 on a downhill grade (slight, away from the pump, and downhill to the left front), I can get a good 2 - 2.5 gallons in after it's clicked off for the first time. It requires a little patience, but I need it to keep accurate fuel mileage records (it has to be the SAME full every tank).

My wife's Volvo does the same (the Ford influence?) - quite annoying.

There is either a big variance is these engines MPG or some of us just don't know how to calcualte it.

1) fill it up (with gas)
2) reset one of the trip mileage indicators
3) drive car until more gas is needed
4) stop and "fill" it with gas"
5) note how much gas it took
6) note how many miles are on the trip meter
7) (using a calculator) divide the number of miles by the number of gallons off the pump.

example: 211 miles/ 13.27 gals = 15.90 :(

I kid here but I seriuosly I have to wonder how many people just take a quess and figure it this way:

1) I drove to work twice (I went about a 100 miles)
2) used less than half tank
3) it holds about 15 gallons
4) let's see 7 is about half of 15
5) 5 is less than 7
6) 100 divided by 5 is 20
7) 20 miles to the gallon WOW

I've been carefully measuring the tank/gauge relationship. I waited until I'd used 1/4 tank, and filled it up to see how much it would be, then repeated this for 1/2 and 3/4 to make sure it was accurate.

I have noticed that even with conservative driving the first half seems to go faster than the second half, although I have no idea why.

Assuming that the 1/4 ... 1/2 ... 3/4 are accurate and that you drive the same way in the same conditions (speed, traffic conditions, temperature, humidity, barometric pressure etc). Then the difference would be due to the added weight of the fuel. 1 US gallon weigh between 5.8 to 6.5 lbs so a full tank (16 gal about 100 lbs) so a half a tank is 50 lbs. I find it hard to believe that 50 lbs could make that much difference, but then again...

I'm convinced that driving style has a lot to do with the mpg. I have about 2300 miles on my car, and I am getting about 21 mpg. My driving consists of 80% hwy driving.

Overall, I'm pretty happy with these numbers because my 2nd gen. RX-7 got about the exact same gas mileage (and I have 100 extra HP in the RX-8). The HP is not exactly free however, because I have to pay almost $1.50 a gallon to feed this one (ouch!).

A lot depends on driving style on any car.

For example, my current car is rated at 18 city, 26 highway and I regularly get around 23 MPG mixed and 28 highway.

How? My driving style, and especially in the city, my shifting patterns. I tend to shift from 1->3->6, with the 1->3 and 3->6 shifts each coming at right around 3K RPM.

Try "short shifting" for a tank with the goal being to get the tranny into 6th as soon as possible without lugging the engine and see what you get for MPG numbers; you may be pleasantly surprised...

lol TJRX8. I feel same way. 20mpg city??? Can't possibly be the same car as my RX-8. I am getting 13-16 mpg w/ 1050 miles on the car & about 80% city, 20% hwy.

Hard to complain about the mpg w/ this car as otherwise awesome as it is. But this is kinda ridiculous. Somethin's definitely amiss....

Originally posted by astrlsrfr
Hard to complain about the mpg w/ this car as otherwise awesome as it is. But this is kinda ridiculous. Somethin's definitely amiss.... With an EPA estimate of 18 city, 24 highway, why is something "definitely" amiss? Yes, it's a bit low, but the Mazda web site, among other places, states:CITY MPG: 18 HIGHWAY MPG: 24

Estimated Annual Fuel Cost: $1238

Actual Mileage will vary with options, driving conditions, driving habits and vehicle's condition. Results reported to EPA indicate that the majority of vehicles with these estimates will achieve between 15 and 21 mpg in the city, and between 20 and 28 mpg on the highway.

ok,ok - calm down billy. Maybe I used some strong words there.
Let me clarify my thoughts on this issue...

I think whats got people disappointed here is that, with the EPA ranges that have been provided - alot of people are sitting at the very low end of those ranges, or even worse - like me - sitting UNDERNEATH those ranges.

Another thing is the fact that w/ all the re-engineering Mazda put into the Renesis, their resulting fuel efficiency seems as low or lower than previous rotories.

Lastly, from the posts I've seen, there's a pretty wide variance wrt mileage. Granted, some of that is to be expected due to driving style defferences. But, we must entertain the possibility that some of these motors might have issues.

So how did Mazda come up with the 20/30 MPG estimates they had on their website for most of the pre-order period? That looks to be about double for what many people are getting in the real world? :confused:

Argh - I used the air conditioner a bit this weekend - and the air condition button appears to activate a hole in the bottom of the gas tank.... At 92 miles I was below 1/2 tank! I filled it this morn - mileage was 12.62 mpg - easy driving, but air on.

I guess I'm gald I got the nav so I can find gas stations - what I don't understand is why the nav is not interfaced to the gas gage so that the car can just redirect you (every couple of days) when it reaches 1/4 tank..... :(

Dave

I have never turned the AC off. On my first ever tank I got 15.5mpg, on the second I got 19mpg. Now I am through break-in I will hit 8k-9.5k rpm about 30 times a day in first/second gear - lets see what happens.

Originally posted by astrlsrfr
ok,ok - calm down billy. Maybe I used some strong words there.
Let me clarify my thoughts on this issue...

I think whats got people disappointed here is that, with the EPA ranges that have been provided - alot of people are sitting at the very low end of those ranges, or even worse - like me - sitting UNDERNEATH those ranges.

Another thing is the fact that w/ all the re-engineering Mazda put into the Renesis, their resulting fuel efficiency seems as low or lower than previous rotories.

Lastly, from the posts I've seen, there's a pretty wide variance wrt mileage. Granted, some of that is to be expected due to driving style defferences. But, we must entertain the possibility that some of these motors might have issues.

I think billy is not the one that needs to calm down.

I don't know how other people are driving, only they know. But, my wife has gotten 20MPG in all city driving, during our break-in period. She did not take the car over 4500 RPM's during this time. Others have gotten similiar city MPG. During a 50/50 city/highway, she got 22 MPG. We are waiting to see with about 25/75 city/highway MPG with her next fillup. It IS possible to achieve the EPA rating on this vehicle. Why are people overestimating the MPG on this car? It is performing as advertised. Let it be.

Originally posted by revhappy
So how did Mazda come up with the 20/30 MPG estimates they had on their website for most of the pre-order period? That looks to be about double for what many people are getting in the real world? :confused:

I don't know if that was the actual estimate on their site. It was too long ago, however figures are subject to change. They note that on their page.

I DO know however that the mileage we have gotten with our vehicle matches the EPA rating on our window sticker. See my previous post to astrlsrfr. Contrary to some doubters here, it is possible to achieve the MPG rating advertised for this car. People need to realize that with an occasional heavy lead foot, your gas mileage will suffer.

Originally posted by MVCalypso
Argh - I used the air conditioner a bit this weekend - and the air condition button appears to activate a hole in the bottom of the gas tank.... At 92 miles I was below 1/2 tank! I filled it this morn - mileage was 12.62 mpg - easy driving, but air on.

I guess I'm gald I got the nav so I can find gas stations - what I don't understand is why the nav is not interfaced to the gas gage so that the car can just redirect you (every couple of days) when it reaches 1/4 tank..... :(

Dave

Not to doubt your 12.62 mpg or whether you are figuring the mpg correctly, but is their a possiblility that you are driving more aggressively (high RPM shift changes and quick acceleration) and doing it more often than you realize?

We have gotten 20 MPG in all city driving. I'm satisfied with our MPG, as advertised.

Originally posted by RX-8 Zoomster


Not to doubt your 12.62 mpg or whether you are figuring the mpg correctly, but is their a possiblility that you are driving more aggressively (high RPM shift changes and quick acceleration) and doing it more often than you realize?

We have gotten 20 MPG in all city driving. I'm satisfied with our MPG, as advertised.

Sigh - ok let's step thru it -
Yes I can do simple math, divding miles by gallons is not hard - I'll bet I can even still do it long hand, on paper, with a pencil. ;)

I am very aware of my driving habits - a few posts back you'll find where I described a full tank of driving as conservatively as possible while still getting the car to actually move - and that only resulted in the 15 range. Fact is I'm getting 13 or lower with 80% highway driving.

Yes I realize that cars do vary within a model - but that variation should not (IMHO) result in only achieving 50% of the advertised milage. My engineering bckground would let me accept a 10%-15% variation - but 50%!?

I would expect the data in the mileage poll thread (as the response sample gets larger) to have a mean response between the 18/24 EAP numbers - but that does not seem to be the case to date.

Originally posted by astrlsrfr
lol TJRX8. I feel same way. 20mpg city??? Can't possibly be the same car as my RX-8. I am getting 13-16 mpg w/ 1050 miles on the car & about 80% city, 20% hwy.
Hard to complain about the mpg w/ this car as otherwise awesome as it is. But this is kinda ridiculous. Somethin's definitely amiss....

Our's must be from the same batch!! :(
How about the suggestions to shift between 3-5k!?!? Why the heck did I buy this car then? I could keep driving my Eclipse and get as good or better performance nailing it every time I hit the gas. And still get better mileage to boot. By no means do I dirve this car HARD a lot but I don't baby the pi** out of it either.

I do LOVE this car but if I would have thought 16 MPG was the best I would get I am pretty sure it would still be a dream and not sitting in my garage. I got rid of a 97 Camaro (that was just a bit faster than my 8) because of the horrendous gas mileage and it got 17 around town and 25 on the Highway. And yes it was the Z28 with a 350.

Originally posted by BillK
With an EPA estimate of 18 city, 24 highway, why is something "definitely" amiss?
I know I sound like a broken record with the number of cars I have owned. It is relevant that I have something to compare too though. Most people I would bet this is their 4th-5th car maybe. But of all the 26 cars I have owned this is the first to not get even the "City" estimate yet. I'm pretty damn sure my driving style hasn't changed in the past month. I still work at the same place I did for the past year so my driving conditions haven't changed. It is 31 miles each way and it takes between 40-45 minutes. I would consider that about 25% City since there are a few stop lights on the way.

If anyone is getting 20 or more than something is wrong with mine period. But it seems that more of us are on the low side than even in the range.

Zoomster, Buy the wife a calculator :D
I'm getting very sad :(

Originally posted by TJRX8


Our's must be from the same batch!! :(
How about the suggestions to shift between 3-5k!?!? Why the heck did I buy this car then? I could keep driving my Eclipse and get as good or better performance nailing it every time I hit the gas. And still get better mileage to boot. By no means do I dirve this car HARD a lot but I don't baby the pi** out of it either.

I do LOVE this car but if I would have thought 16 MPG was the best I would get I am pretty sure it would still be a dream and not sitting in my garage. I got rid of a 97 Camaro (that was just a bit faster than my 8) because of the horrendous gas mileage and it got 17 around town and 25 on the Highway. And yes it was the Z28 with a 350.

I'll have to see what I get when I start driving my car. I'm quite sure that it will be lower than what my wife is getting. I'm much more into aspirated driving. :D But, I'm not really concerned about the MPG I'll get, since I didn't consider that a factor (good MPG) in my decision to buy this car in the first place. I loved the way it looked and wanted the fun factor of driving it.

Originally posted by RX-8 Zoomster
But, I'm not really concerned about the MPG I'll get, since I didn't consider that a factor (good MPG) in my decision to buy this car in the first place. I loved the way it looked and wanted the fun factor of driving it.

I know what you're saying Mark. The car rocks...But dang a weekend of driving was $25 and I didn't go anywhere. BTW my girlfriend lives in South Tampa 30 miles in the opposite direction of work. So I simple day of go to work and out to dinner is about 125 miles and almost 15 Bucks in PREMIUM gas! It adds up quick, hence the reason I only have 1500 miles in one month. Still driving the Eclipse :( most of the time.

Quick numbers based on 20,000 miles per year driven and the current cost of gas in my area:

20,000/25mpg=800 gals * $1.48 (reg) = $1184 per year (Eclipse)
20,000/16mpg=1250 gals * $1.68 (prem)= $2100 per year (RX8)

Cry me a river :( Man try living in Canada where your gas price is almost DOUBLE what your paying!

I am not flaming or anything I understand your concern, as I went from a car with excellent mileage to the RX8 that is pretty bad too. But ....

From the numbers you just gave I did a little comparison.

Right now the price for regular is 78.8 cents a liter! So premium is 10 cents more or 88.8 cents a liter.

Ok so this means nothing to you I'm sure.

Well: 1 US gallon = 3.7854118 liters
And the exchange rate is approx: 1.4 right now from US to CDN $

So at $1.48 (reg) a gallon you are only paying 55 cents cdn a liter!
at $1.68(prem) a gallon you are only paying 62 cents cdn a liter!

Man I ONLY WISH! We haven't seen prices that low for 2 years or more!

Ok, so lets go the other way to give you a better idea.

If you came to Canada, heck Ottawa is one of the cheaper places to get gas, some places are up to 10 cents more a liter, although I know it's similar in the US.

Ok so here's the break down. If you drove up here to get some gas.

Regular would be $2.13 a gallon and premium would be $2.40 a gallon.

Now just be glad you aren't paying that!

Oh wait, is someone from the UK going to chime in? Man they pay like $2 a LITER maybe more!

Originally posted by Wing
Cry me a river :( Man try living in Canada where your gas price is almost DOUBLE what your paying!


if i were from arizona i'd say "atleast you have gas!" but i'm not so... i'll just say my mileage has steadily been improving. i'm at 1500 miles now and i started off at 13mpg and now im at 18.8mpg was a non linear gain tho, after that first tank i got 16mpg, then 17, then high 17, then 18

Originally posted by Wing
Cry me a river :( Man try living in Canada where your gas price is almost DOUBLE what your paying!!
Congrats!

I lived in the U.K. as well as Germany and Japan. Japan had the most expensive gas of them all.

EAST MOON! how much is it now?

Anyway I live in the good ole US and my prices are what I based it on just for comparison. The thread is based on MPG not $PG.

Cry me a river...of gas that is, looks ike I'll need it.

MPG is annoying at this point, even when averaging around 18. we actually broke the mythical 20 on the last tank that was 95% highway.

What drives me absolutely crazy though is to own a vehicle that could get as little as 200 miles to the tank! Regardless of actual efficiency, no car should get less than 300 miles to a tank. It's incredibly annoying to have to fill up so often. There are places in the western US where I will have to think twice about whether I want to drive the next leg or short tank it to make sure I can reach the next gas station. That's just rediculous!

This was my biggest gripe in the Miata. It's now my biggest gripe with the RX-8. I want a car that can get 300 miles per tank with some reserve so I don't have to panic about gas at the 250 mile point.

I was very hopeful when I figured it had a 16 gallon tank and looked to be able to average well over 20 on the highway. Now I'm happy when I get over 200 before the last 1/4. Very depressing! If it was going to be this thirsty, fine, but put in a BIGGER gas tank to compensate.

Edge to state the obvious...

Gas = heavy.

Idea of RX-8 is lightweight sports car.

Thus.... :D

ALso, I personally am seeing a twice repeated 365 miles to a tank with 95% highway cruising (80-90 MPH range) and 5% city (just to get on the open road).

Also, the more I drive it (at just voer 1000 miles now) the betetr it's getting overall. My lowest was 13MPG with a lot of AC/city driving, and have gotten that up to 16 so far.

Originally posted by Edge
MPG is annoying at this point, even when averaging around 18. we actually broke the mythical 20 on the last tank that was 95% highway.

What drives me absolutely crazy though is to own a vehicle that could get as little as 200 miles to the tank! Regardless of actual efficiency, no car should get less than 300 miles to a tank. It's incredibly annoying to have to fill up so often. There are places in the western US where I will have to think twice about whether I want to drive the next leg or short tank it to make sure I can reach the next gas station. That's just rediculous!

This was my biggest gripe in the Miata. It's now my biggest gripe with the RX-8. I want a car that can get 300 miles per tank with some reserve so I don't have to panic about gas at the 250 mile point.

I was very hopeful when I figured it had a 16 gallon tank and looked to be able to average well over 20 on the highway. Now I'm happy when I get over 200 before the last 1/4. Very depressing! If it was going to be this thirsty, fine, but put in a BIGGER gas tank to compensate.

You should be able to reach or exceed 300 highway miles with your "mythical" 20 MPG's. This has a 16 (15.9) gallon tank. Even if you figured 15 gallons, @ 20 MPG's, it will get you to 300 miles.

Hercules is right, this is a lightweight sports car. This is not a touring sedan. Add a 20 gallon tank, and more body length to support it (if you don't want to decrease back seat or trunk room), you are talking about much more weight. Hence you have less performance, because you have to haul around all that extra weight with the same size engine. You'll end up getting less MPG's then you have now

Honestly, and this is not directed specifically to you Edge, people knew about (or should have known) the EPA rating before they bought the car. If they felt it was not economic enough for them to drive and be satisfied, then they should have looked at other vehicles. Myself and others have gotten MPG's equal to the EPA rating. Although it was not all aspirated driving, it still was obtainable. I am perfectly happy to have a vehicle I can drive agressively and be fun, even though my MPG's can drop to 15. If I decide to take the car out and want to travel a long distance, I can drive more conservatively and know that I can get around 24 MPG's, as advertised.

Originally posted by Hercules
Edge to state the obvious...

Gas = heavy.

Idea of RX-8 is lightweight sports car.

Thus.... :D

Hate to restate the obvious (can we beat this dead horse to death more please) I bought a GT (last I checked that stood for Grand Touring). In other words I expected a package that would allow me to cruise with my kids in the back for loooong distances.

Second obvious point, gas aint that heavy. 4 extra gallons would add no more than 32 pounds. Yes I know we need some extra tank to go with it, but is it really that much heavier? I doubt it. An empty 5 gallon gas can doesn't weigh much. Maybe make that muffler a little smaller and steal some of the room and weight. It certainly won't have near the impact that the sun roof addition had.

Last obvious point, the idea of the RX-7 is a light weight sports car. The RX-8 can't really lay claim to that title any more IMO. Yes it's amazingly light for what it does, but they didn't come in at 2900 like they wanted. 3000+ is significantly fatter than some cars i've driven that also carried 4 people comfortably.

"365 miles to a tank twice repeated"?
"close to 24 MPG on the Highway"?
"300 miles to the tankful"
"MPG equal to the EPA rating"
on and on and on

Fact: we as a group are not "averaging" between 18 and 24.
Fact: no one has hit 24 mpg yet
Fact: we knew about the EPA of 18-24 not 13-20
Fact: something is not right

I am open to suggestions and learning new things like "driving". Please please post the steps I need to take to get 18-20 miles to the gallon without towing it.

I am tempted to go fill up to the brim then head south on I-75 at Midnight with the cruise set to 55 until I run out of gas. Then I'll call my Mazda roadside assistance to tow me to the nearest gas station (I won't count those miles either). Then fill it to the brim again, write down the gallons and mileage numbers. I'll post them here for you math wizards to crunch and please pelase tell me I got at least 18.88 MPG.

Any takers? You have to promise to put down the pipe though. :D

Originally posted by TJRX8


I am tempted to go fill up to the brim then head south on I-75 at Midnight with the cruise set to 55 until I run out of gas. Then I'll call my Mazda roadside assistance to tow me to the nearest gas station (I won't count those miles either). Then fill it to the brim again, write down the gallons and mileage numbers. I'll post them here for you math wizards to crunch and please pelase tell me I got at least 18.88 MPG.

Any takers? You have to promise to put down the pipe though. :D

Tom,

LOL! You just might have to do that. Do it when I get back and you can call me. I'll bring you a gas can full of gas, and meet you down in Naples or somewhere on that god-forsaken alligator alley.

And I promise to put down my hookah which I bought over here. ;)

I just finished my third tank of gas and got 253 miles (mostly city driving) and filled up with 14.8 gallons. The first 150 miles was before break-in so I changed gear typically between 3000 and 6000 rpm. The last 100 miles and half a tank was after break-in so I revved the nuts off the car - all gearchanges up from 1st and many from 2nd were done between 7000-8000rpm (perhaps exceeded 7000rpm over 30 times).

So I averaged 17.1mpg without trying too hard in mostly city driving and always with the air-con on. I think 20-24mpg is easily attainable - not that I care. Once I hit 1000 miles and my first oil change I will be hitting 9000+rpm pretty often...

Originally posted by pelucidor
- not that I care. Once I hit 1000 miles and my first oil change I will be hitting 9000+rpm pretty often...

Welcome to the club. :D

Originally posted by RX-8 Zoomster

And I promise to put down my hookah which I bought over here. ;)
I don't even wanna know :)

BTW: Alligator Alley does suck but can you imagine what driving to Miami or the Keys must have been like back in the day?!

And with this bad gas mileage....never mind :D

i live in LA and am about to buy the RX-8 unfortunaly though this might make me very reluctant to do so...gas in LA is over 2.20 a gallon if you go to 76 for 91 octane...are 16 gallons thats 35 bucks a fill. and i drive about 500 miles to 800 miles a week and if i get like 250 miles a tank well thats almost 100 bucks a week in gass and that comes out to over 5 grand a year in gas...hell i should start to drive my old expedition with that i can fill it up with 89 octane and get 400 pluss a tank...

but no one has made any points about how the car is missing about 20 hp and about 4 mpg....something should be brought up to mazda...heck i might just buy a rx8 now just to bitch at mazda for making the car slower than the new dodge neon and have the fuel consumption of a ford 4.8l v8 supercharged...cause my friend with his harley edition f150 is getting about 15.3 mpg

can the people getting good mpg please check out what their exhaust tips look like?

First tank was 15 mpg - ok I'll concede I did spend a good 2 hours practicing start on that tank so I didn't think much of it. Now I just got 17 mpg driving like a complete granny, 1-3-5 or 1-3-6 shifting all the time, never getting above 4k rpm and doing most shifting around 3k... ok, I did nail it one time to run with a Stang GT but that was like 5 sec of fuel usage. You know what - its making me start to hate the car with a passion driving it like a 90 hp kia rio.

I only have 300 miles on the car and my exhaust is completely coated something fierce with black soot. This thing has to be running as rich as a top fuel dagster for gods sake to develop that amount of soot. LoL... and I was going to shell out $300 for exhaust finishers - I'd have to clean them every frikkin day just to be able to see them on my black car :mad:

Originally posted by crazydrifter


but no one has made any points about how the car is missing about 20 hp

They do now. LINK HERE (http://www.rx8forum.com/showthread.php?s=&threadid=9347&perpage=15&pagenumber=1)

Originally posted by pr0ber
can the people getting good mpg please check out what their exhaust tips look like?


I got 18.97 on the first tank and 23.2 on the second. I've got a little over 600 miles on the car. My exhaust looks like someone spilled toner all over the inside of it. :)

Seriously - most of it is driving style; perhaps Mazda should have enabled an upshift light.

Simply put, if you shift at 6000 RPM you're going to get worse mileage than if you shift at 3000, and the name of the game in mileage is to get to sixth gear as fast as possible.

Try this city folks - shift 1->3->6, shifting at around 3000 RPM from 1->3 and into 6th as soon as you get to speed. Odds are the engine will be turning at around 1000 RPM and 40 MPH or so. Do this for a week and see what your mileage is.

Also, be sure you never idle longer than one traffic light; being stuck in traffic sucks gas like there's no tomorrow.

As far as highway MPG is concerned, what speed are you going? I assume you are driving in sixth, but most cars suffer a drop in MPG at speeds of 70 MPH and above due to increased drag. Set the cruise at 60 MPH and see what kind of mileage you get; it will be higher than what you get at 75. Don't forget to hack off 1-2 MPG if you have the rear spoiler.

There are those who will cry "3000 RPM? Why did you buy a car like this?" Hey, feel free to rev it high, but remember doing so comes with mileage consequences.

Originally posted by BillK
Seriously - most of it is driving style; perhaps Mazda should have enabled an upshift light.

Simply put, if you shift at 6000 RPM you're going to get worse mileage than if you shift at 3000, and the name of the game in mileage is to get to sixth gear as fast as possible.

Try this city folks - shift 1->3->6, shifting at around 3000 RPM from 1->3 and into 6th as soon as you get to speed. Odds are the engine will be turning at around 1000 RPM and 40 MPH or so. Do this for a week and see what your mileage is.

Also, be sure you never idle longer than one traffic light; being stuck in traffic sucks gas like there's no tomorrow.

As far as highway MPG is concerned, what speed are you going? I assume you are driving in sixth, but most cars suffer a drop in MPG at speeds of 70 MPH and above due to increased drag. Set the cruise at 60 MPH and see what kind of mileage you get; it will be higher than what you get at 75. Don't forget to hack off 1-2 MPG if you have the rear spoiler.

There are those who will cry "3000 RPM? Why did you buy a car like this?" Hey, feel free to rev it high, but remember doing so comes with mileage consequences.

Good post BillK! Ditto on every point.

OK, after several tanks of terrible mileage, I just decided to ignore it and drive the car. I expected the mileage to drop when I went back to running the air conditioner and shifting above 3k - much to my suprise the mileage has increased significantly for the last tank. Weird.

Here are the things that changed: 1) the total OD for the last tank was between 750-950 ( change in ECU mapping?); 2) I happened to change gas brands (from Chevron to 76). 3) Same combo re city/freeway driving - no sig change in pattern.

On the immediately prior tank I got 13.63 MPG; on this tank I got 15.62... that's a 24% difference. The best I had been able to do before was 15 wtih all granny driving and no air.

Wish I knew whether to attribute this to the gas brand or the total mileage. Guess I won't really know until I track things for a few more tanks. I'll be sticking with 76 for while to eliminate that variable.

Of course I'm still a long way from even the EPA city estimate. Perhaps if I keep the fingers crossed and continue sacrifcing virgins to the MPG gods... Or I suppose I can decide to have terrible angst over the horse power issue and let Mazda have the car back.

Dave

Took a quick trip from Dallas to Austin last Thursday and paid close attention to my MPG. This was about 98% highway due to the fact that I live just blocks from the highway and my destination was a mere 6 blocks from the freeway exit. I had the air on and took it easy on my speed keeping it under 70 most of the way. I took advantage of cruise control when I could and didn't do any aggressive driving. Anyway...I only got 21.3 MPG but expected more for driving like grandma. My city driving is aggressive and I feel lucky to get the trip meter over 200 before the low fuel light comes on. My 4000 pound Pickup truck with it's 5.7 V8 gets slightly better mileage than my 8 but isn't doesn't quite have the same driving experience :)

DeBug

From http://www.fueleconomy.gov/feg/driveHabits.shtml


Drive Sensibly

Aggressive driving (speeding, rapid acceleration and braking) wastes gas. It can lower your gas mileage by 33 percent at highway speeds and by 5 percent around town. Sensible driving is also safer for you and others, so you may save more than gas money

Fuel Economy Benefit:
5-33%

Equivalent Gasoline Savings:
$0.07-$0.49/gallon

---------------------------------------------------------------------------------

Observe the Speed Limit

Gas mileage decreases rapidly at speeds above 60 mph. Each 5 mph you drive over 60 mph is like paying an additional $0.10 per gallon for gas. Observing the speed limit is also safer.
http://www.fueleconomy.gov/feg/tips/SPEED.gif
Fuel Economy Benefit:
7-23%

Equivalent Gasoline Savings:
$0.10-$0.34/gallon

---------------------------------------------------------------------------------

Avoid Excessive Idling

Idling gets 0 miles per gallon. Cars with larger engines typically waste more gas at idle than do cars with smaller engines

---------------------------------------------------------------------------------

Use Cruise Control

Using cruise control on the highway helps you maintain a constant speed and, in most cases, will save gas.

---------------------------------------------------------------------------------

Use Overdrive Gears

When you use overdrive gearing, your car's engine speed goes down. This saves gas and reduces engine wear.
---------------------------------------------------------------------------------


//////////////////////////


For the record, I have a big problem with the way the EPA figures the MPG ratings for vehicles.

from http://www.fueleconomy.gov/feg/info.shtml#estimates:

---------------------------------------------------------------------------------


How are fuel economy estimates obtained?

The fuel economy estimates are based on results of tests required by the U.S. Environmental Protection Agency (EPA). These tests are used to certify that vehicles meet the Federal emissions and fuel economy standards. Manufacturers test pre-production prototypes of the new vehicle models and submit the test results to EPA. . EPA re-tests about 10% of the tested vehicles to confirm manufacturer's results in EPA's lab. The vehicles are driven by a professional driver under controlled laboratory conditions, on an instrument similar to a treadmill. These procedures ensure that each vehicle is tested under identical conditions; therefore, the results can be compared with confidence.

There are two different fuel economy estimates for each vehicle in the Fuel Economy Guide, one for city driving and one for highway driving. To generate these two estimates, separate tests are used to represent typical everyday driving in a city and in a rural setting. Two kinds of engine starts are used: the cold start, which is similar to starting a car in the morning after it has been parked all night; and the hot start, similar to restarting a vehicle after it has been warmed up, driven, and stopped for a short time.

The test used to determine the city fuel economy estimate simulates an 11-mile, stop-and-go trip with an average speed of 20 miles per hour (mph). The trip takes 31 minutes and has 23 stops. About 18 percent of the time is spent idling, as in waiting at traffic lights or in rush hour traffic. The maximum speed is 56 mph. The engine is initially started after being parked overnight. Vehicles are tested at 68 F to 86 F ambient temperature.

The test to determine the highway fuel economy estimate represents a mixture of "non-city" driving. Segments corresponding to different kinds of rural roads and interstate highways are included. The test simulates a 10-mile trip and averages 48 mph. The maximum speed is 60 mph. The test is run with the engine warmed up and has little idling time and no stops (except at the end of the test).

NOTE: To make the numbers in the Fuel Economy Guide more useful for consumers, EPA adjusts these laboratory test results to account for the difference between controlled laboratory conditions and actual driving on the road. The laboratory fuel economy results are adjusted downward to arrive at the estimates in the Fuel Economy Guide and on the labels seen on new cars, light trucks, and vans. The city estimate is lowered by 10% and the highway estimate by 22% from the laboratory test results. Experience has proven that these adjustments make the mileage estimates in the Fuel Economy Guide correspond more closely to the actual fuel economy realized by the average driver.
---------------------------------------------------------------------------------



I don't see this 'test' preceedure changing- based on the sales of trucks and SUVs. This is done on a treadmill??? So the aerodynamics of the vehicle have NO effect on the EPA's numbers, and even then they DON'T even go faster than 60mph? What a bunch of BS. No wonder vehicles can really suck the gas on the interstare when going 80mph when compared to the EPA 'rating'.:( And they never give the vehicle more fuel than what is needed, and no hills. (no full throttle :confused: )
Anywho, keep in mind that they don't test with the a/c on, and have wide sticky tires really has a less effect on a treadmill only running the drive tires than on the hot pavement with all four running.
You guys not getting very good fuel economy numbers with your RX-8s, try running the tires at closer to maximum pressure and keeping the car in the highest gear possible until you absolutely must have the extra power. My bro bitches about the fuel economy of his Miata, but he 'cruises' around in third gear all the time, even when going a steady 60mph. We have had arguements about this when I am forced to ride with him. :mad:
Also, try running incognito on the highway. When I drive on the interstate or any four lane, I always stay as far right as possible. That way when and if you are speeding, you will attract much less attention from the police. But it also lets you get some draft off of other cars/trucks on the highway. Better fuel economy and less speeding tickets.:p

Just finished another tank of 93 Octane and got a whopping 16!!! mpg. Combined but mostly Highway speeds and very little horsing around.

To BRealistic. Thanks for lots of info, and I agree with most of what you say, but there is one statement that makes me wonder. You say there are no hills (simulated, of course, on the treadmill) in the EPA test. I looked at what seemed to be the same EPA page you printed, and didn't see anything to back that up. They talked about the course including typical rural and highway roads. I would bet even money they dial in the gentle grades of interstates and occasional steeper ones to imitate typical rural roads. But I'm just guessing. If anyone knows, speak up.

To BRealistic. Thanks for lots of info, and I agree with most of what you say, but there is one statement that makes me wonder. You say there are no hills (simulated, of course, on the treadmill) in the EPA test. I looked at what seemed to be the same EPA page you printed, and didn't see anything to back that up. They talked about the course including typical rural and highway roads. I would bet even money they dial in the gentle grades of interstates and occasional steeper ones to imitate typical rural roads. But I'm just guessing. If anyone knows, speak up.

RX-8, I don't appreciate your condescending attitude. You tell us that your wife has achieved good mileage with careful driving. And you at least strongly imply that the rest of us either don't know how to drive for economy, or are whiners.
I see. You know how I drove my car when I got terrible mileage. You have taken apart my RENESIS, and know that it is capable of giving good mileage. You're a remarkable fellow.
I am more patient than some of you young folks (I'm 71), so I have continued to do granny driving through a 1,000 mile breakin period with my auto. That means very rarely hitting even 5,000, and spending almost all the time between 1,500 and 3,000. With much more vigorous post-breakin driving, I have attained EPA highway mileage in many other cars.
My car, ordered the day after they started taking orders, was an early build. The evidence seems to show that it is not performing up to par. With all due respect, I will trust my reasoning power over your comments.
Mitch

Originally posted by Mitch Strickler
..., I have attained EPA highway mileage in many other cars.
My car, ordered the day after they started taking orders, was an early build. The evidence seems to show that it is not performing up to par. ...Mitch
Yeah. What he said!

Originally posted by Mitch Strickler
RX-8, I don't appreciate your condescending attitude. You tell us that your wife has achieved good mileage with careful driving. And you at least strongly imply that the rest of us either don't know how to drive for economy, or are whiners.
I see. You know how I drove my car when I got terrible mileage. You have taken apart my RENESIS, and know that it is capable of giving good mileage. You're a remarkable fellow.
I am more patient than some of you young folks (I'm 71), so I have continued to do granny driving through a 1,000 mile breakin period with my auto. That means very rarely hitting even 5,000, and spending almost all the time between 1,500 and 3,000. With much more vigorous post-breakin driving, I have attained EPA highway mileage in many other cars.
My car, ordered the day after they started taking orders, was an early build. The evidence seems to show that it is not performing up to par. With all due respect, I will trust my reasoning power over your comments.
Mitch

Mitch,

I assume you are talking to me. If so..... I don't appreciate your condescending accusations. And my aren't we the sensitive fellow.

I was just making a point that there are many factors involved in how one gets results in their MPG's. Driving techniques, driving conditions, driving enviroment, and the vehicle you drive. Only you can determine what is factoring in if you have lower gas mileage. If you don't think your problem is not any of the first three, then obviously you think it's your car. My car seems to be getting as advertised. And quite a few here got close to EPA results in less than desirable driving conditions also. That not to say you're car is not the culprit.. But I feel it is not a widespread problem common to every car. But that's MY opinion. And you don't have to be a smartass to suggest that I think the engine is not responsible in some cases.

In all due respect, I also trust my reasoning power from the results I am getting. If you don't like mine or anyone's elses advise, suggestions, or experiences, and wanting to share that, then you are more than welcome to ignore them. And if you misintrepet my comments as me having a condescending attitude - I say to you - so what?

Mitch, I'm sorry that the RX-8, to you, does not meet all your expectations. If you are really unhappy or disappointed in the vehicle because of the gas mileage, you now have a "free" option to opt out with Mazda's buyback. Then, you'll have the opportunity to purchase a vehicle that may be more energy conscious for you.

Or if you feel that the RX-8 is the right car for you, I hope your mileage will improve through time or via a "fix" if it turns out to be a problem with your engine.

P.S.
Let me add that I am not insensitive to those that feel the car is performing submar in the area of MPG's. If it turns out to be a widespread problem, then I do sincerely hope that Mazda can "fix" whatever might be wrong, and everybody will be happier.

Originally posted by TJRX8

Yeah. What he said!

HEY! ;)

Just finished my 4th tank and got slightly over 18mpg. Car has a total of 907 miles now, mostly Houston (i.e. city) driving and always with aircon on and windows closed. I tend to go up to 6000rpm in 1st gear and sometimes goto 9000rpm in 1st and 2nd (hear the chime regularly). I would say I redline about 10+times a day. However I also tend to use 5th and 6th a lot when there is no scope for spirited driving (e.g. dawdling in traffic at 30-40mph), or during steady 85mph highway speeds.

I am slightly disappointed in the fuel economy, but it is improving by leaps and bounds as the engine breaks in - my first tankful averaged 15.5mpg and I never exceeded 6000rpm (mostly stayed at 3000rpm). My average over 900 miles is 17mpg and rising. Lots of soot on the tailpipes every day too, and no oil needed so far.

These comments are not directed at anyone in particular; it's more of an observation I've had in this RX-8 forum and is a generalization of what Mitch said. Some of us have observed "anomolies" in our cars (low mpg and cycling a/c come to mind.) Others don't observe those problems. Those that don't typically make some constructive comments (is a/c set to recirc or what RPM do you shift at, etc.) However, once that has been established they tend to not believe those of us reporting the problem. Like, "Are you sure you're not redlining?" or "Are you sure you've set your a/c temp to low?" This starts to get annoying to the point of condescending. Yes, we know how to operate a/c. Yes, I know how to drive like granny. And yes, my a/c still cycles and I get 17 mpg under the very best of circumstances (15.5 is more typical.) You'd think I'm reporting that I'd seen Sasquatch and the unbelievers out there are calling my bluff. While we do express many different opinions in this forum, when we objectively state observations (as opposed to expressing opinions) please believe that other members know what they're talking about. I think this is what Mitch was reacting to, and I have to admit it does get annoying at times. Some of us, despite our best efforts, are getting piss-poor mileage. Now, let's get down to work and see if we can figure this out so we can hold Mazda accountable. After all, isn't sharing our knowledge to optimize our RX-8 experience what this forum is all about?

I agree with Mitch and 8_wannabe. Thanks for the constructive comments. To me, I think some people think we are bashing the RX-8, and are trying to defend it vohemently. This is simply not the case. We just want to know why our cars are missing their stated mileage claims by so much, and so consistently.

I for one, will be speaking to my dealer this week about the buyback option. My plan is to buy a new RX-8 w/ the NAV option. I originally wanted to get this - but was unwilling to wait for it in a later allotment. So now I get a second chance :)

I will explain to my dealer about the poor gas mileage situtation w/ my current 8 , and that I expect it to be resolved, should I repurchase another one. I figure its prolly just a tuning issue with certain early 8s, and its been quietly resolved. Hopefully, at the very least, they will have a fix for this and a TSB will be made available.

Hey astrlsrfr, welcome to the forum and to the family of San Diego owners. We had a rally last month and planning another sometime soon; check for thread in the western region area. and thanks for weighing in on this issue.

Originally posted by Mitch Strickler
To BRealistic. Thanks for lots of info, and I agree with most of what you say, but there is one statement that makes me wonder. You say there are no hills (simulated, of course, on the treadmill) in the EPA test. I looked at what seemed to be the same EPA page you printed, and didn't see anything to back that up. They talked about the course including typical rural and highway roads. I would bet even money they dial in the gentle grades of interstates and occasional steeper ones to imitate typical rural roads. But I'm just guessing. If anyone knows, speak up.

double post! :p

Yeah, you may have a point. I looked at all this EPA stuff a year ago, when my truck wasn't even close the EPA highway number even when driven like a granny. But recently I got a tank over the EPA hwy number, and it was mixed hwy and city- so who really knows how the get the best fuel economy. It really shocked and pissed me off when I saw the 'scientific lab testing' done. WTF. Never going OVER 60mph? Because of the strict CAFE regulations and steep fines, it is only logical than the auto manufacturers would be designing their vehicles engine mapping and trans gearing for the best EPA results without regard for real world conditions.:mad:

One thing to remember, the rotary engine has different metals sandwiched together. When they are cold and the different metal parts havn't fully expanded, they are very inefficient.
Also, any new vehicle owner can demand the dealer do a fuel consumption test, to verify that the car is running properly and using fuel at an acceptable rate. If they refuse, then use the 'buy-back' card to sway their opinion. Of course, they may want a used like new low miles RX-8 to resell, so who knows.
On the buy-back thing: What happens if you traded in a vehicle on your RX-8?

Originally posted by BRealistic
On the buy-back thing: What happens if you traded in a vehicle on your RX-8? You get your money back for the RX-8.

Obviously you sold your trade-in to the dealer and were paid an amount for it in credit against the RX-8. That's exactly what you'll get back.

Originally posted by pelucidor
Just finished my 4th tank and got slightly over 18mpg. Car has a total of 907 miles now, mostly Houston (i.e. city) driving and always with aircon on and windows closed. I tend to go up to 6000rpm in 1st gear and sometimes goto 9000rpm in 1st and 2nd (hear the chime regularly). I would say I redline about 10+times a day. However I also tend to use 5th and 6th a lot when there is no scope for spirited driving (e.g. dawdling in traffic at 30-40mph), or during steady 85mph highway speeds.If you really want to try and get the MPG on the sticker, you probably know you can't keep going to 6K and sometimes 9K in 1st and 2nd. Likewise, you can't go down the highway at 85MPH. Of course I'm sure the state patrol could help you with that one. :D

Seriously, to improve your mileage, try just driving the speed limit; remember as you go much faster than 60 MPH wind drag will start bringing down your MPG precipitously...

Filled mine up again last night. This time it was a combination of city driving, a 200-mile country trip including considerable time spent at or near triple digits, and about 40 autocross runs. 14.71mpg. I was expecting much worse.

Originally posted by eccles
...............about 40 autocross runs.

WOW! What about tire wear?

Thanks, 8_wannabe and astrlsrfr. You understood exactly what I was saying, and said it better.
The idea of using the buyback and then getting a new car sounds promising, especially if you have one of the cars that was built early -- I was told April 19 -- and then took a suspiciously long time to deliver (tinkering with subpar engine?).
It's not for me, though. In a perfect confirmation of the saying that no good deed goes unpunished, I was within a few hundred yards of the place where I volunteer to read for the blind when an 80 year old woman, upset because she had lost her way going to the hospital, decided to go from the middle lane (of 3) to a right-hand turnoff. She hit four out the five panels on the left side of my car.
The guys at my dealer's body shop thought it might be months before they get the parts for the repair. The car runs fine, but I am worried what will happen when they repair the outer part of the four-welded-panels "ring" that is a key structural part.
Mitch

Originally posted by Mitch Strickler
I was within a few hundred yards of the place where I volunteer to read for the blind when an 80 year old woman, upset because she had lost her way going to the hospital, decided to go from the middle lane (of 3) to a right-hand turnoff. She hit four out the five panels on the left side of my car.

Maybe she was one of the ladies you were supposed to read to. LOL. Anyway, bummer about the car. If you can get pix, start another thread and post 'em. You must have a 14-yr-old grandkid who can do digital photos for you. ;)

okay i dont want to be rude to anyone of you cause heck i dont know you well enought to B**ch slap you but you really are going to listen to the EPA when they dont test rotary motors? hears the deal with your RX8...first off you get lower gas mileage on any car when you have the A/C and with the more electronics you have on when driving the car..with that said if you read about your RX8 the 18 mpg in the city is a average the epa got...that means you should get between 15-21 mpg...well no one here so far has gotten to 18 but here is why...first off granny driving makes the rotary motor burn more gas...instead of shifting at 3000rpm shift at 7000 but dont floor it to 7000....agressive driving is when you floor your car.... i will tell you guys how in my opinion a rotary motor works when it comes to gas...you could say its like a bike...for example lets say you have a 21 speed bike and its in 12th gear...if you start from a stand still it takes more leg power to get the wheels to start to spin but once you get them spinning it gets much easier and you dont have to put in as much leg power...just like a rotary...when you rotary motor is at 3000rpm its like being in the 12th gear and going slow...and when you get the car above 5000 its like being in 12th gear and going relatively faster so the motor doesnt need harder combustion to get the rotar to spin fast like the motor did when going from 1000rpms to 3000rpms....if you dont under stand this just pm me....i found this to be true cause when i went to the dealer to ask about mpg they told me that you get better gas milage the longer you stay in gears...and if you read the post most people getting good mpg are driving the car not granny driving...

Originally posted by MVCalypso
I talked to Mazda cust service earlier this week and asked what could be done - they suggested that I have the dealer "run a fuel consumption test" - so I plan to have that done (what ever that is - hopefully it is something other than having a mechanic put 200 miles on the car :( ) - just as soon as I find a dealer that I think knows anything about a rotary engine...


Thanks for the suggestion: I also called Mazda customer service and they referred me to the "fuel consumption test." Spoke next with the service tech at the local dealer and guess what... the test is exactly what you jokingly said. They keep the car for a week, drive it around, take it home at night to validate the claim of low mileage. I seriously thought he was joking, but he wasn't. So I asked, let's say you validate my claim of low mileage, how does driving it around help diagnose the problem? The answer to that is, as they drive it's hooked up to a computer that takes some kinda readings to verify settings and metrics.

I dunno... the whole thing sounds kinda screwy to me. But since I'll be out of the country all next week and when I get back I need to decide whether or not to return the car, what the heck... drive away! I'll have them do this test and I'll post the results sometime after Sept 9th after I get the car back. If they find a way to get me 20 mpg (vice the ~16 I've been getting) it'll be worth it to me. If not, I give back the car. It's a no-lose proposition but they'd better not put 800 miles on this car while I'm gone.

By the way, the service tech also told me: stay away from gas with methyl-ethyl alcohol. As he put it, this is just a "filler" that sucks down your gas mileage. He says Chevron and Shell do NOT use these so they should give better results. I usually buy gas on the Navy base (Navy exchange); don't know if they use these fillers or not. Does it say on the pump? Will it say how much they've added? And, is it true what this guy is saying? I've seen people on this forum say Shell and Chevron are better, but they cited different reasons (additives like Techroline.) I never believed these wive's tales, but the alcohol theory sounds plausible. Can any of our hydrocarbon experts weigh in with knowledgable info on this (not opinions, guesswork, or "my brother he" stories.)

You should ask them to hook up the computer then YOU drive it around all week. I'm not positive but it shouldn't take a Mazda tech to just drive around....

Originally posted by highspeed8
You should ask them to hook up the computer then YOU drive it around all week. I'm not positive but it shouldn't take a Mazda tech to just drive around....

What a concept, 8. If their computer is really logging the right metrics they'll be able to see how I'm driving. Plus, after owning this for 5 weeks I trust myself better to drive serenely than some techie who's got his one chance to "see what it'll do." The only setback is, I won't be able to do this till after my trip. Add time for corrective actions on their part, if any. Leaves me a couple weeks to decide about keeping the car or not. They told me I need to decide by Oct 1 on the turn-in deal.

BTW, lest I be flamed, the 9 hp problem is completely inconsequential to me. But if I knew the 8 would get such poor mileage I never would have bought it. It's expensive and socially unconscienable in my book. The fact that I'm getting a second chance to return the car is just serendipitous as far as I'm concerned. There is no other "problem" with the 8 that makes me unhappy enough to return it since the "fun factor" outweighs everything else. However, if I gotta drive like grandma the car is no longer fun and that's a big problem for me. If I can get at least 20 mpg by trying, and less when having fun, that's good enough. Right now, I'm not even close.

This mileage stuff is insane. Do you all suppose it's going to get better with break in? I would also say the "9hp problem" is more like a 30hp problem. But youare right, as long as the car is fun to drive that's what matters most.

Gas mileage HAS NOT improved after break-in.. I'm getting the same.. actually have adjusted my driving, so I'm still getting about 215 to a tank, but only filling up once a week so It's normal for me now I guess.. hopefully something will get fixed to change this.. so instead of me driving a car with 247hp and getting 13mpg, I'm driving a 180 hp car and STILL getting 13mpg! Where's the justice?! I love it tho :)

yup 8_wannabe - count me in.

Just went through another tank & you guessed it - 13.6 MPG. :(

I called John Hine, here in SD where I bough the car and spoke w/ a service guy about the mileage. He was implying that the Califonia 8s have more emissions & are heavier than other states. I thought they just built them all to meet California emissions??? Sounds like flim-flam to me. Anyone can comment on this?

Originally posted by BillK
If you really want to try and get the MPG on the sticker, you probably know you can't keep going to 6K and sometimes 9K in 1st and 2nd. Likewise, you can't go down the highway at 85MPH. Of course I'm sure the state patrol could help you with that one. :DSeriously, to improve your mileage, try just driving the speed limit; remember as you go much faster than 60 MPH wind drag will start bringing down your MPG precipitously...
Funny how this is the only car I have ever owned that I needed a bunch of know-it-alls on a forum telling me how to drive to obtain EPA MPG. I never really gave it much thought how different I drive this car than the 25 others I've owned. I usually use A/C if it's hot, I drive over the speed limit sometimes, I roll my windows up and down depending on the weather, sometimes I shift in the power band, sometimes I don't...blah blah blah.

Guess I ain't smart enuff to own this perdy lil sports car. Guess I'll have to opt for the buy-back and look for a dumber car that's easier to drive properly.

Did I say I love this car? ;)

Originally posted by astrlsrfr
yup 8_wannabe - count me in.

Just went through another tank & you guessed it - 13.6 MPG. :(

I called John Hine, here in SD where I bough the car and spoke w/ a service guy about the mileage. He was implying that the Califonia 8s have more emissions & are heavier than other states. I thought they just built them all to meet California emissions??? Sounds like flim-flam to me. Anyone can comment on this?

astrlsrfr,

You definately seem to have a car with MPG problems.

I curious to know if you have one of the earlier allocation of cars or a low VIN#. I started a thread Does specific VIN#'s = problematic cars? (http://www.rx8forum.com/showthread.php?s=&threadid=9600) to see if we can collect data on whether owners that problems correlate to a specific VIN range, etc.

In regards to your emissions question... I believe you are right. I seem to recall reading that all the RX-8's are the same emissions standard. There is not two different "emission versions".

Originally posted by TJRX8
Funny how this is the only car I have ever owned that I needed a bunch of know-it-alls on a forum telling me how to drive to obtain EPA MPG. I never really gave it much thought how different I drive this car than the 25 others I've owned. I usually use A/C if it's hot, I drive over the speed limit sometimes, I roll my windows up and down depending on the weather, sometimes I shift in the power band, sometimes I don't...blah blah blah.The Renesis is probably just more sensitive to driving behavior than many other engines are. This type of thing happens all the time with various vehicles and it's just the way the EPA testing process works.

People have been saying the EPA numbers are wrong or are impossible to achieve; they're not. EPA numbers are often difficult to reproduce, and I suspect the fact that the RX-8 is a sporty car makes it doubly difficult to reproduce because people tend to drive it harder than they would a Camry.

When I owned an Audi TT, I remember some people on the TT board complaining about the gas mileage they were seeing. It turned out that for many "normal" driving involved high RPMs and turbo use. I never used my turbo except on a highway on-ramp and often shifted around 3K and would regularly almost get EPA highway numbers midway between city and highway in mixed driving. Likewise I've rode with friends in their cars and have asked them why they were beating the crap out of their engines by revving them to 5K or 6K before shifting. They laughed and told me "it's a car, it's meant to be driven" and later would tell me about their sub-par gas mileage.

So, IMHO, are the EPA numbers "lies" or "unachievable"? No. Are they for some people's driving styles? Perhaps...

Originally posted by BillK
The Renesis is probably just more sensitive to driving behavior than many other engines are. This type of thing happens all the time with various vehicles and it's just the way the EPA testing process works.

So, IMHO, are the EPA numbers "lies" or "unachievable"? No. Are they for some people's driving styles? Perhaps...

I would like to believe this, however it seems no matter what I do to my car (baby it or flail it) I get around 16-something mpg. Other folks have said no matter what they, they get around 21. Obviously, you can't flair it for 200 miles and expect that, but my point is there seems to be two variants of the car: Hi-mileage ones and low-mileage ones. It's weird...

Everyone keeps talking about "how to drive" the car, where and when to shift, redline vs. no redline. But nobody is mentioning the main cause of poor gas mileage - speed. Since acceleration lasts for only a few seconds, whether you shift at redline, or at 3000 rpm, that will only slightly impact your gas mileage. Cruise speed will influence gas mileage MUCH more, since that is where the majority of driving occurs.

If you cruise at 85 mph, you're going to get crappy gas mileage compared to cruising at 60 mph; no matter what car you drive. So, you have a choice, do you want to drive fast, or do you want to get good gas mileage? If you want to drive fast, then deal with the lower gas mileage. If you want good gas mileage -- SLOW DOWN!

End of rant. :)

Originally posted by jonalan
Everyone keeps talking about "how to drive" the car, where and when to shift, redline vs. no redline. But nobody is mentioning the main cause of poor gas mileage - speed. Since acceleration lasts for only a few seconds, whether you shift at redline, or at 3000 rpm, that will only slightly impact your gas mileage. Cruise speed will influence gas mileage MUCH more, since that is where the majority of driving occurs.

If you cruise at 85 mph, you're going to get crappy gas mileage compared to cruising at 60 mph; no matter what car you drive. So, you have a choice, do you want to drive fast, or do you want to get good gas mileage? If you want to drive fast, then deal with the lower gas mileage. If you want good gas mileage -- SLOW DOWN!

Only partially right, and even then an oversimplification. First, acceleration makes a huge impact, particularly for city and short-term freeway driving (as in, when you can't just set cruise and off you go.) Secondly, it's engine speed not necessarily roadspeed that'll kill you. I could drive 60 and get crummy mileage. Why? Because I'm in third gear. Same road speed, same wind resistance, different engine speed. In 6th gear at 3000 rpm you're going maybe 65 or so; that oughta be about optimal economy. I could comment further on your post, but I should more properly put it under the Flaming Jerks (http://www.rx8forum.com/showthread.php?s=&threadid=9635) thread.

Edit: Done. If you want to discuss low mileage of the car, please post here. If you want to discuss my ancestry or other non-sequitors please go the to Flaming Jerks thread.

Originally posted by astrlsrfr
yup 8_wannabe - count me in.

Just went through another tank & you guessed it - 13.6 MPG. :(

I called John Hine, here in SD where I bough the car and spoke w/ a service guy about the mileage. He was implying that the Califonia 8s have more emissions & are heavier than other states. I thought they just built them all to meet California emissions??? Sounds like flim-flam to me. Anyone can comment on this?

I routinely get 13.5 MPG using an RX-8 delivered in Richmond, VA.

Originally posted by msrecant
I routinely get 13.5 MPG using an RX-8 delivered in Richmond, VA.

How many miles you got on the car now? I just topped 2000. My mileage was down in the 15's, now I've gotten 17.5 mpg the last two fillups. I shift routinely at 3000 rpm but still have a heavy foot on the freeway. I use regular (87 octane), just filled up with Shell as I was told they (and Chevron) don't add methyl ethyl alcohol, which reduces mileage. I don't know if that story is true but I'm determined to solve this mystery by the end of sept when I have to decide whether to keep the car.

Originally posted by 8_wannabe


How many miles you got on the car now? ...

Just passed 1,100. I was averaging 13.5 so this last tank I was very careful to shift at 4,500 RPM or lower, get it into 6th (or 5th) ASAP and to do minimal downshifting. That got me some very dull driving and roughly 15 MPG. Who says driving habits don't change gas mileage :) .

I use premium but I will have to check if the methyl ethyl alcohol is an additive routinely used in VA.

I got concerned about other, comparably powered cars getting better gas mileage. I spent an afternoon researching on the Internet and discovered all the other cars get their performance from higher engine torque and lower rear-axle ratios. The RX-8 4.444 ratio is a killer for gas mileage. Even in 6th, the effective ratio is still higher that the 350z, which is heavier and has more power but gets better gas mileage.

OTOH, we might just be being rewarded for getting early (mid July) delivery.

Originally posted by msrecant


Just passed 1,100. I was averaging 13.5 so this last tank I was very careful to shift at 4,500 RPM or lower, get it into 6th (or 5th) ASAP and to do minimal downshifting. That got me some very dull driving and roughly 15 MPG. Who says driving habits don't change gas mileage :) .

I use premium but I will have to check if the methyl ethyl alcohol is an additive routinely used in VA.

there are a lot of imponderables and unknowns in this equation, but two things I have come to believe as "truth." One, shifting at 3000 rpm will save gas. I initially shifted at 4500 like you and got mid 15's on mileage. At first, 3000 shifts were psychologically hard for me but now I'm used to it. I occasionally run it up to 4500 or more if I gotta get around an idiot quick.

Second, using regular or premium will not affect your mileage. with regular, you will give up a few HP but you won't notice the difference. I and many others have tried, and can't tell. Plus I have an email from Mazda saying (1) It won't affect mileage and (2) It won't hurt the engine (by means of the anti-knock sensor.) I spent a lot of time running this to ground.

That ethyl methyl stuff can be found in any grade of octane, it's more a function of what brand of gas you buy. I'm still looking into this. Finally, the most imponderable of all is what did Mazda do -- if anything -- to the ECUs at the port? Did they tweak them or something for EPA thereby messing up both hp and mileage? At this point I think only Mulder and Sculley can unravel this mystery.

the website of the dealer where i ordered my 8 has their inventory listed and 30 of the 93 rx-8's have ULEV in their description including mine. does this have any bearing on whether my car will be a gas hog or not?

I haven't read all the posts, but - I just finished a 6400 km road trip from Alberta to California and back - that's around 4000 miles. No babying, any cruising was done at 75 to 85 mph, and the slower stuff was including a lot of downshift/full throttle for passing on two lane roads or hard accelerating in the hills and twisties. Overall, I got 19.8 mpg, with the mileage at the end of the trip a bit better than at the start. The absolute lowest I could manage to get was 15.6 mpg, and several legs were at 22+ mpg.

Regards,
Gordon

Originally posted by Gord96BRG
I haven't read all the posts, but - I just finished a 6400 km road trip from Alberta to California and back - that's around 4000 miles. No babying, any cruising was done at 75 to 85 mph, and the slower stuff was including a lot of downshift/full throttle for passing on two lane roads or hard accelerating in the hills and twisties. Overall, I got 19.8 mpg, with the mileage at the end of the trip a bit better than at the start. The absolute lowest I could manage to get was 15.6 mpg, and several legs were at 22+ mpg.


What... you came all the way down here and didn't even drop in to say hi!? :D Hey, sounds like a great trip and thanks for the datapoints. Strange that you would be better mileage at the end. After all, it's downhill all the way from Canada to US and uphill all the way back, right?

Ok, I was pretty hard the on 8 for the first while aftder the break in.. I was pretty gentle with the 8 on break in, but that means nothing (more like very little) above 6000 rpm, and only a few 100% throttle stints.

my first fillup at 230 miles 13.5 gallons = 17.0 mpg

fillup #2, 200 miles, 13.3 gallons = 15mpg

I've always been getting the oil burnoff resudue on the inside of my muffler tips.. I'm wondering how heavily the inside of the exhaust (and cat?) are coated with that carbon deposit.

More recently (I've got 2500 miles on it now) I filed up at 223 miles for 12.5 gallons = 17.8 mpg.

The best mpg I've experienced so far, has been on a long drive from detroit to indianapolis. I achived 80 miles for each 1/4 tank marker. I filled up just after the light came on 13.8 gallons for 285 miles = 20.6 mpg (almost 100% driving at 80 mph)

I figure it should be possible to get 320 miles out of a full tank before being stranded on the side of the road.. ;)

I'm counting on Mazda to fix the crummy ECU setup. I'm going to call them and bitch about it. The dealer is just going to slow down my complaints. I've used only premium gas so far, and will definately try regular soon. I want my missing 50 horses (yes it could be that much) and 5 to 8 mpg back.

I figure the $500 madza is offering will only pay for the delta in gas costs from what they listed for about 6 months.. Planning to keep this car about 7 years means that they need to fork over another $6500 to make that up....

OverLOAD, the pattern you describe is starting to sound pretty typical. It's pretty much the same as me except I haven't taken an extended road trip yet. Good luck in your call to Mazda; let us know what, if anything, you get out of them.

I thought that I would not care about MPG in the RX8 but
I have driven 1571.6 miles and put 108.6 gal, which is average of 14.5 MPG. Two tank full were freeway trips (18.7 & 19.1 MPG).
I admit that I run the air conditioner and stomp on it once in awhile (well maybe twice a day) and drive 70-90 MPH on the freeways but I have made an effort to go slow to see what the MPG should be and got pretty much the same 14MPG.
Yes I took care during the break-in. The break-in MPG was 12.7 to 14MPG.

I really like the RX8 but I may consider returning it and then buy one when things are more consistent. My Vin JM1FE173040106438.

From reading the forum, other are getting much better MPG. What is your experience?

One posting mentioned that MPG gets a little better after 2000 miles.

RX8 GT Blue

I may give the dealer a chance to see if they can find something wrong and also checkout my Air Conditioner (same problem as others). Although it is good some days and not so good others. I am going to place a digital thermometer in my car and take some data.

Originally posted by pcorsaro
Sorry I thought I was placing this under Milage thread. New user and still learning this Forum stuff.

I thought that I would not care about MPG in the RX8 but
I have driven 1571.6 miles and put 108.6 gal, which is average of 14.5 MPG. Two tank full were freeway trips (18.7 & 19.1 MPG).
I admit that I run the air conditioner and stomp on it once in awhile (well maybe twice a day) and drive 70-90 MPH on the freeways but I have made an effort to go slow to see what the MPG should be and got pretty much the same 14MPG.
Yes I took care during the break-in. The break-in MPG was 12.7 to 14MPG.

I really like the RX8 but I may consider returning it and then buy one when things are more consistent. My Vin JM1FE173040106438.

From reading the forum, other are getting much better MPG. What is your experience?



One posting mentioned that MPG gets a little better after 2000 miles.

RX8 GT Blue


I may give the dealer a chance to see if they can find something wrong and also checkout my Air Conditioner (same problem as others). Although it is good some days and not so good others. I am going to place a digital thermometer in my car and take some data.

I'm going to merge your thread with the thread about this topic in the Tech Garage seciont. You'll get a lot more responses (and be able to read a lot more) in there.

I've posted several time before in this thread re the mileage I'm (not) getting from my RX-8 - here is the latest update.

Yesterday I had to make a semi-local business trip for the day - 150 miles each way. The OD started a bit over 1000 miles. I filled up the night before and left the house in the morn - light traffic the entire trip. Filled again upon arrival - result: 20.4 MPG over 2.5 hours freeway cruising, 30% on cruise control, no air running.

For the reverse trip home: 19.4 MPG - ran the air the entire trip (needed in the afternoon), a bit more traffic than in the morn.

Both legs were run at the prevailing speed of traffic (which varied from 45 to 85 - I just went with the flow).

Gee, best my car can do is achieve City EPA estimates with 100% freeway driving under cruise control.

Alas, the theory re 2000 miles making a difference is something I probably won't have a chance to test - as I don't expect to get to 2k before the 10/1 decision deadline... The ineffciency of the car is making me lean toward selling it back. I don't want (or care about) steller MPG figures, I just want the car to operate as advertisedl... and I can honestly say that if the window sticker had said 13/19 (my averages) I never would have considered the 8.

Dave

Originally posted by MVCalypso
Alas, the theory re 2000 miles making a difference is something I probably won't have a chance to test - as I don't expect to get to 2k before the 10/1 decision deadline... The ineffciency of the car is making me lean toward selling it back. I don't want (or care about) steller MPG figures, I just want the car to operate as advertisedl... and I can honestly say that if the window sticker had said 13/19 (my averages) I never would have considered the 8.

Are you considering contacting Mazda customer support (phone)with your MPG issue? If so, I would be interested in hearing what they have to say. I was not planning on even starting work on my MPG problem until I hit my 3K checkup.

Anyway, good luck, and hope it turns out that you can get things resolved and keep the car!

Originally posted by msrecant


Are you considering contacting Mazda customer support (phone)with your MPG issue? If so, I would be interested in hearing what they have to say. I was not planning on even starting work on my MPG problem until I hit my 3K checkup.


What they do is refer you to your dealer for a fuel consumption test. That consists of your dealer keep the car several days/up to a week and driving it around with instrumentation attached to verify mileage. Not sure what they do after that. Two of us (at least) have gotten this story.

We just got back from a trip from the DFW area to Chicago and back. Air was on all the time except for a few hours one morning. We averaged around 21 mpg. The best we got was a little over 22mpg when the air was off for about 1/2 tank. At least it's better than the 13 we've been getting in town.

I put in 1/2 quart of oil at 1300 and the other half at 2600 to keep the oil level light from coming on at high speed.

Originally posted by MVCalypso
... I don't want (or care about) steller MPG figures, I just want the car to operate as advertisedl... and I can honestly say that if the window sticker had said 13/19 (my averages) I never would have considered the 8.Dave
Ayup True dat!

Originally posted by jd62
I put in 1/2 quart of oil at 1300 and the other half at 2600 to keep the oil level light from coming on at high speed.
What is considered high speed that your oil light is coming on?

Ya know it'd be interesting to see a Dyno of someone getting good gas mileage. Gotta wonder what their HP is and whether their dyno will have a Dip in it around 6700rpm.

Originally posted by MVCalypso

Both legs were run at the prevailing speed of traffic (which varied from 45 to 85 - I just went with the flow).You do know that that right there will take a big bite out of your highway mileage, right?

Remember, mileage at highway speeds drops off sharply above 60 MPH; the much-maligned 55 MPH speed limit wasn't chosen by throwing darts at the wall.

Run a tank on the highway at no more than the posted speed limit and see what you get...

Originally posted by TJRX8

What is considered high speed that your oil light is coming on?

The oil level light came on at about 78 and went out after slowing to about 74. The level on the dipstick was about 1/3 down from full.

Originally posted by jd62
The oil level light came on at about 78 and went out after slowing to about 74. The level on the dipstick was about 1/3 down from full.
I have about 1700 miles and just checked the oil again. It is right at half and I haven't added any yet nor has the oil light come on.
BTW I get it up to at least 80 everytime I take it out.

Originally posted by TJRX8

I have about 1700 miles and just checked the oil again. It is right at half and I haven't added any yet nor has the oil light come on.
BTW I get it up to at least 80 everytime I take it out.

I think the later VIN cars have better baffling in the oil pan. My VIN is 2178 build 6/3 and I think I have the old oil pan which causes the oil light problem.

Originally posted by jd62

I think the later VIN cars have better baffling in the oil pan. My VIN is 2178 build 6/3 and I think I have the old oil pan which causes the oil light problem.
10xx VIN and 5/28 build. hmmm now what? :confused:

Anyway another fill-up today:
13.3 gallons and a whopping 214 combined miles traveled:

16.09 MPG and climbing :)

Originally posted by BillK
You do
Remember, mileage at highway speeds drops off sharply above 60 MPH; the much-maligned 55 MPH speed limit wasn't chosen by throwing darts at the wall.

Run a tank on the highway at no more than the posted speed limit and see what you get...
Posted speeds are 70-75, maybe that's my problem. I need to see if Jeb will lower the speed limits again! :D

Originally posted by TJRX8

10xx VIN and 5/28 build. hmmm now what? :confused:

Anyway another fill-up today:
13.3 gallons and a whopping 214 combined miles traveled:

16.09 MPG and climbing :)


It's good that it's climbing. Weird that some cars start out with good MPG right out of the shoot while some have to "age". If all things were equal we could point to the ECU potentially assuming average driving patterns and obeying the break in period, etc. as being the culprit and holding the engine back until it was loosened up but that doesn't seem to be the case. Also at 2,000 miles things seem to really get interesting around 6000 rpm in terms of power. Keep us posted.

Isn't it possible that the older cars in the first allocation that sat at port for a few weeks were flashed with different ECU settings than later production cars? Maybe Mazda has come up with new, "better" settings after having a little more time to test/tweak.

I just wonder if that would help explain the differences we're seeing in mileage figures. My car was built 6/23/03 and so far I have been getting 22-23 mpg consistently after 19 the first tank. I've been driving pretty aggressively the last couple tanks and my highway speeds vary anywhere from 60-80. My daily commute is 80/20 highway/city, and I've got a little over 1100 miles on the car now.

Originally posted by loco4rx8
Isn't it possible that the older cars in the first allocation that sat at port for a few weeks were flashed with different ECU settings than later production cars? Maybe Mazda has come up with new, "better" settings after having a little more time to test/tweak.

I just wonder if that would help explain the differences we're seeing in mileage figures. My car was built 6/23/03 and so far I have been getting 22-23 mpg consistently after 19 the first tank. I've been driving pretty aggressively the last couple tanks and my highway speeds vary anywhere from 60-80. My daily commute is 80/20 highway/city, and I've got a little over 1100 miles on the car now.

Yes I agree this is a good explanation. I was looking at it as a static ECU for all cars but Mazda might be tweaking it as it gets more and more feedback.

Originally posted by RX-GR8
Also at 2,000 miles things seem to really get interesting around 6000 rpm in terms of power. Keep us posted.

Interesting good or interesting bad? I've had crappy gas mileage up till now, but at 2000 miles seeing my mileage start to improve. I have NOT had that power loss above 6250 that some have reported. Please don't tell me I'm gonna start seeing a power loss!

(btw, I have not been guilty of accusing people of inventing the 6250 power loss or not knowing how to drive. I wish those without the mileage or a/c problems would stop accusing those less fortunate of making this stuff up. It is really getting tiresome. This rant is not directed at RX-GR8, but many others in this forum.)

Originally posted by 8_wannabe


Interesting good or interesting bad? I've had crappy gas mileage up till now, but at 2000 miles seeing my mileage start to improve. I have NOT had that power loss above 6250 that some have reported. Please don't tell me I'm gonna start seeing a power loss!

(btw, I have not been guilty of accusing people of inventing the 6250 power loss or not knowing how to drive. I wish those without the mileage or a/c problems would stop accusing those less fortunate of making this stuff up. It is really getting tiresome. This rant is not directed at RX-GR8, but many others in this forum.)

Interesting good. Sorry I should have been more explicit. I read on this forum some owners stating that at about 2000 miles the power seemed to increase at 6200 rpm whereas before the port seemed to be stuck or there was hesitation..

Originally posted by RX-GR8


Interesting good. Sorry I should have been more explicit. I read on this forum some owners stating that at about 2000 miles the power seemed to increase at 6200 rpm whereas before the port seemed to be stuck or there was hesitation..

I think these people had a power problem at 6200 and ultimately the problem goes away. Since I'm not seeing that problem there should be no change for me. I think these theories about different versions of the ECU sound pretty plausible. This is the type of mystery I hope BOOSTD7 can unravel in his investigations with Mazda. If I have a substandard ECU burn, I'd like to know (1) Will my ECU sooner or later behave like those who are getting full power and full mileage, or (2) Can they reprogram my ECU to more favorable mpg's like some people seem to be getting from Day 1.

I am feeling your pain. I am keeping track on my latest fillup but its been awful so far. I've got about 500 miles on it and am beside myself on how bad the gas is. I would think the aluminum hood and pedals would push this thing to at least 40 mpg, don't you? Thats a joke.

Seriously, I demand at least 20. I will be gripping to the dealer too if I cant get it to at least 17. Below that is embarrassing, no matter how you drive. And I drive pretty conservatively.

I will look at the manual for the shift points though. But what fun is that. If I wanted some dang robotic shift points, I would have bought an automatic.

Originally posted by SPEEE DE
I will look at the manual for the shift points though. But what fun is that. If I wanted some dang robotic shift points, I would have bought an automatic.

In desperation when I was getting 15 mpg I started following the recommended shift points, namely shifting at 3000 rpm. It was awful, just like you said. I did it for one full tank, got 16 mpg, did it for another half tank before I said the heck with it. It TOTALLY removes all fun from having the 8, for a gain of 1 mpg? I don't think so.

Now, I'm back to my old ways, but I've learned new bad habits (like efficient driving ;) ). I often shift now at 3K and I don't mind it so much anymore, but whenever I feel like it I rev it higher, meaning several times on any given outing. My mileage continues to rise (now up to 17.5.)

I am convinced that poor mileage has nothing to do with "bad" driving habits (within reason.) I've read many posts from people who regularly rev to 6K and are getting above 20 mpg without even trying. There are two versions of this car out there: Low mileage and high mileage. If I had to bet, it has to do with the ECU. I think we will get to the bottom of this, hopefully within the next few weeks (are you listening, Mazda?) because the polls on this forum show that more people are concerned about poor mileage than about less hp on paper. I would bet more cars will be returned for the mpg reason than for any other unless Mazda can help us sort this out.

On the money 8_wannabe, as usual.

Gotsta be the ECU. Its the most plausible explanation, given the total confluence of info: the port hangup, the HP drop, and the drastic varation of MPG amongst different 8s. I wish knew how to check the firmware version. And, of course, I wish we knew how to flash it.

We creep closer and closer to October 1st, and Mazda continues to seemingly pretend this is not a problem. No recall. No TSB. Not even a quiet word to the dealers. They either don't understand the problem themselves, or they are living a fantasy that 8 owners don't really care about the MPG as much as this forum indicates they do, or they have already fixed the problem in new 8s, and are going to quietly let the buyback take care of the issue. I'm thinking its the later.

Since my car is one of the "sick" ones (and I don't mean "sick" in the newish positive form of the word . 13 MPG is the norm for my 8), I am leaning heavily in that direction. I will wait until the last week of September. If there is no fix at that time, my car is going back.

Great car. Lots of drama. This has to be one of the most fascinating new car experiences I've ever had. I am very happy to have the internet, and this forum. Think how screwed up all this would be if we couldn't communicate like this.

Originally posted by TJRX8

Posted speeds are 70-75, maybe that's my problem. I need to see if Jeb will lower the speed limits again! :D Well 75 is still lower than 85, so run a tank no faster than the posted limit and see if it makes a difference...

I drive on highway about 60 % of the time at 70 - 90 mph, and in the city at normal speed. I accelerate quickly a lot of the time, and run the A/C in 90 + weather all the time. I have about 700 miles on the car and I have been getting about 200-mpg average each tank of 91 gas. Just giving the facts for me.:)

So your getting what 12-14mpg, thats friggin terrible.

So your getting what 12-14mpg, thats friggin terrible.
The mileage sucks but I did not buy it for the mileage. I love the drive and I do not give a damn about the mileage. I have a economy car for that. So your right the mileage sucks, but I love it anyway :D

So your getting what 12-14mpg, thats friggin terrible.


That may not be true. It depends how low he's letting the tank go. I also have a little over 700 on my car and have been filling up about every 200 miles (when the meter is around 1/4 mark).

200 miles--11.696 gallons = 17.09 MPG
220.1 miles--12.551 gallons = 17.53 MPG
200 miles--13.055 gallons = 15.32


The big drop was due to hitting 600 miles on the car and bouncing off the rev limiter frequently :D


Edit: The first tanks were not granny style driving. Reasonably hard acceleration but less than WOT and shifting just under 6K RPMs.

That may not be true. It depends how low he's letting the tank go. I also have a little over 700 on my car and have been filling up about every 200 miles (when the meter is around 1/4 mark).

I say I fill up just below 1/8 tank. I am sure if I stopped the lead foot driving, and the Max Cooling of the air, it would be O.K. But what is the fun in that?? :)

Originally posted by msrecant


Are you considering contacting Mazda customer support (phone)with your MPG issue? If so, I would be interested in hearing what they have to say. I was not planning on even starting work on my MPG problem until I hit my 3K checkup.

Anyway, good luck, and hope it turns out that you can get things resolved and keep the car!

Yes, I have contacted Mazda - they suggest having a dealer run a "fuel consumption test" - I'm currently looking for a dealer that meets two criteria:
1) Has a mechanic that has at least some rotary experience and
2) knows what a "fuel consumption test" is...

The dealer I purchased from fails both criteria - I intend to get the test done, but I want it done by someone that has what I would consider minimal competence in the topic at hand - guess I'm feeling picky...

Dave

Originally posted by BillK
You do know that that right there will take a big bite out of your highway mileage, right?

Remember, mileage at highway speeds drops off sharply above 60 MPH; the much-maligned 55 MPH speed limit wasn't chosen by throwing darts at the wall.

Run a tank on the highway at no more than the posted speed limit and see what you get...

One has to understand what I'm trying to evaluate - I'm trying to decide if the car has satisfactory performance (and MPG is one metric of performance) at a cost level (gas is a cost) acceptable to me. If I feel the balance is good - or at least meets my expectations, I'll keep the car, if not it goes back. The reference to "expectations" is deliberate - my expectations wrt to MPG were set by the Mazda's specs - which my car can't seem to meet.

I can't control traffic speed while driving. If one drives to slow, you get in trouble for "impeding the flow of traffic", if one drives to fast, you also get noticed and get in trouble for "speeding" - so I tend to drive with the flow - which is therefore my "normal driving environement". In "my normal driving environment" the car has to be worth what it costs me - the MPG issue is, at this moment a large negative for me. To make the point extreme: I don't care if the car gets 1000MPG on Mars - as I don't drive it on Mars... where I live (No. CA), 55MPH might as well be on Mars :eek:

Dave

Originally posted by BillK
Well 75 is still lower than 85, so run a tank no faster than the posted limit and see if it makes a difference...
I'm trying, but in this car...dang is it tough!

I have driven my RX-8 for 2,625 kilometers so far ( 1631 miles)
The average mileage I have so far is 16.83 miles per US gallon.

Lots of highway runs at higher speeds make up the majority of this mileage. Around 15% has been in town and 85% on highway runs at pretty high speeds.

On highway averaging around 150kmh ( 93mph) I get around 16.5 to 17mpg.

As miles accumulate i do not see any noticeable trend in mileage getting better or worse, so break-in seems to be irrelevant.

Okay...tank of 87 is now history.
224 miles and 14 gallons equals exactly 16 mpg. So the last 3 tanks of various grades I got:
15.9
16.09
16

20xx on the odo.

Originally posted by 8_wannabe


I am convinced that poor mileage has nothing to do with "bad" driving habits (within reason.) I've read many posts from people who regularly rev to 6K and are getting above 20 mpg without even trying. There are two versions of this car out there: Low mileage and high mileage. If I had to bet, it has to do with the ECU. I think we will get to the bottom of this, hopefully within the next few weeks (are you listening, Mazda?) because the polls on this forum show that more people are concerned about poor mileage than about less hp on paper. I would bet more cars will be returned for the mpg reason than for any other unless Mazda can help us sort this out.

Interesting observation, and it got me to thinking - could there be an association between poor mileage and power loss above 6K?

The reason I wonder this is that I have neither problem, and I wonder if it's coincidence. BTW, my car was built 5/30 and delivered 7/22, for anyone interested in the 'different ECU mapping' theory.

Last 3 tanks for me were 18.3 with 93, 18.5 with 89, and 19.3 with 89. First tank as I recall was about 15MPG - didn't start recording until there seemed to be a lot of interest in it from the forum. I also don't think driving style really is affecting MPG much - I love to hear the Renesis wind up to 9K! Odo is currently at about 1350. I fully expect to be above 20MPG soon, and mileage has been better than my RX-7 since day 1, so I'm satisfied with both mileage and performance.

Finally, I'm not expecting any miracles at 2000 miles, but then again, I'd be happy to be the recipient of a few more ponies.

Hi to all those who read this message. This is my first post. I just purchased an RX-8 (manual transmission) two days ago and so far i'm extremely happy.

I wanted to let everyone know what my mileage was after my first fill-up. I bought the car with 11 miles on it, drove 1 mile to the gas station, filled up the tank and drove it for 2 days. I put 11.1 gallons in and my odometer read 260 miles. So i put roughly 248 miles and used 11.1 gallons which gave me about 22 miles per gallon. I drove it in town about 25% of the time and the rest was on the freeway traveling between 70 and 85 mph with the A/C on all the time. I hope my gas mileage stays this good or gets better (if i'm lucky).

I have owned one 84 RX-7, and two 93 RX-7's. The 84 got about 20 mpg at it's best and the 93's generally got between 16 and 19 mpg. So far the RX-8 has been the best. I can't get over how smooth this new Rotary engine is. I'm 100% happy so far.

Great results for your first tank - you should see more improvement down the road, although you will be driving it a lot harder after 600 miles (we hope)! Congrats on your purchase and welcome to the forum.

I had mine for 10 days and 750 miles. I went through the break-in, e.g., first 100 under 4k rpm, 2nd hundred under 5k, 3rd under 6k, 4th under 7k, 500 under 8k and no limit after 600 miles. The first tank gave me 16.3 mpg; the second tank, 17.1 mpg; the third tank (mostly highway at 75-85 mph with a few runs up to 110-120) gave me 20.2 mpg. I haven't finished the last tank yet, but it's looking like 17-18 mpg and I'm pushing to 9k in first and second where I can. IMHO, not bad at all for a green engine!:)

Last tank gave up 18.3 mpg after 221 miles 1/2 hwy, 1/2 a mix but with numerous runs up to 9k+ in 1st, 2nd and 3rd. This after 800+ miles.:D

Originally posted by MVCalypso
.... I don't care if the car gets 1000MPG on Mars - as I don't drive it on Mars... where I live (No. CA), 55MPH might as well be on Mars :eek:
Dave
Amen brother! I couldn't have said it better myself, except substitute "Central Fl." for "No. CA".
:cool:

I'm currently in my breakin period and I'm getting 14.8mpg on my second tank of gas. The car currently has 330 miles on it.

My take offs are quick, my freeway driving habits are varied because I'm not supposed to keep the engine running at the same RPM for long. So I would be going from 65mph in one minute and 90 in the next. The most I rev it up to is 7K rpm and that's not often. I usually shift between 4k and 5k rpm.

My driving is 50/50 highway/city. I keep my windows open majority of the time.

I may be able to get 20mpg if I take it easy and keep the windows closed... But I probably won't do that until I'm well pass 600miles.

I'm currently using Chevron 91 octane.

-John

you gas should improve
I started with 13mpg and after about 2k I started getting better mpg. Now the car has over3k and is getting 18mpg

Wow. 214 miles/12.3 Gals= 17.4 mpg.

87 Octane, TSC/DSC off, 50/50 city/hwy, driving the piss out of it sometimes, 2500 miles total.

This is the best I have gotten so far, previously 16.09 was best.

Hi guys,

quick mileage update:

I have about 800+ miles on my car and I have noticed that my fuel economy has improved. I am not sure what its due to, but its definitely better.

255 Miles from 13.419 gallons = 19.003 MPG

Now my first tank was freaky and I never took the car over 6k RPM.

182 Miles from 14.011 gallons YIKES!

If I can get to 20+ and still be allowed a few runs to 9k RPM, I'll be a very very very happy man. right now I'm just very very happy! :-)

I'm dreaming of 14mpg... after more than 2000 miles I still don't have 13mpg... last tank gave me 12.51 mpg:eek: ....

Bye bye 8!

15.5 on the last tank. :(

your gas should improve around 2k

I commute 54 miles each way, all highway with some hills, and I've gotten 18.5, 19.5, 19.6 mpg (averaging 80mph) while using 91 octane fuel. I've got just under 900 miles on my car at this point. I'll be quite please if my fuel efficiency keeps increasing until 2000 miles, as has been observed.

I was getting a solid 200 miles per tank.

Now I am at 1100 miles and I am driving exactly the same with the A/C always on HIGH and I and just over 250 miles per tank.

Something is happening and its a good thing.

I'm at 2600 miles, and mileage has been steadily improving. I got a personal best of 18.6 last night, and that was on a tank doing everything "wrong." I stopped watching my shift points, used low-octane (87) gas, DSC/TC on, a/c on, lotsa revvin', etc. And got better mileage than ever. I've heard it also improves after the first oil change which I oughta do soon, so I'll keep my fingers crossed.

On last, which included about 80 highway in 6th gear. Low were the first 2, at around 14.5. High was 20, which included long highway drive to the mountains (and then a little fun). Just over 1K miles. Sure hope reported improvement at 2K occurs!

Shifting philosophy varies -- half time trying to improve MPG results; other half reminding myself why I bought the car.

Originally posted by shebam
Shifting philosophy varies -- half time trying to improve MPG results; other half reminding myself why I bought the car.

Great point, shebam, and welcome to the forum. In trying to follow everyone's advice and shift/drive efficiently, I polluted myself with so many "bad" habits that the car was no longer fun to drive. I finally reasoned that, what if I got 24 mpg and drove all day long like grandma? Would I be content? Realizing I wouldn't, I abandoned all modes of efficient driving, started having a little fun again, and found that my mileage kept improving (above 2000 miles) regardless of what I did.

Now at 3136km (1949 miles).
Last tank was all city.
This tank I babied it. Shifted up to 5th from 2nd, 6th from 3rd, etc. keeping rpm below 4000.
Not much change:
in 198km, got 16.7l/km / 14.12MPG.

Hoping it might change soon!!

Just an update. I'm up to my third tank now in my 8. Here are the MPG data so far.

14.8 mpg - breakin period 326 - ending miles
16.9 mpg - breakin period 526 - ending miles
16.2 mpg - breakin period 741 - ending miles

My driving habits vary since its the breakin period. I tried to vary the RPMs on all gears and at all speeds. I drove like a grandma and also like a grandson at times. But never rev it above 6k rpm.

I hope it gets better mpg soon... I have a feeling that it would be able to meet EPA's rating.. I think.. =-]

-John

Originally posted by canzoomer
Now at 3136km (1949 miles).
Last tank was all city.
This tank I babied it. Shifted up to 5th from 2nd, 6th from 3rd, etc. keeping rpm below 4000.
Why are you using 5th at all?

For maximum gas mileage, just think "as soon as I get to speed, shift into 6th." You also should probably shift 1->3->6.

For example, on a normal street, you can usually start in 1, shift into 3rd and be cruising in 6th any time you are going faster than around 35 MPH...

Originally posted by BillK
Why are you using 5th at all?

For maximum gas mileage, just think "as soon as I get to speed, shift into 6th." You also should probably shift 1->3->6.

For example, on a normal street, you can usually start in 1, shift into 3rd and be cruising in 6th any time you are going faster than around 35 MPH...

I tried this for awhile and the car is so not fun driving this way, I shoulda got a Metro. Besides which there was no detectable improvement to gas mileage. I finally decided, "if I wanted a three speed then why did I buy a six-speed?" and went back to my normal, fun driving techniques. As I did that and total mileage increased, my mpg started going up. I don't think this driving technique helps, it strips away all fun from the '8, and I'm still trying to unlearn the habits gained while doing it. IMHO!

Originally posted by 8_wannabe


I don't think this driving technique helps, it strips away all fun from the '8

I agree with you 100%. Driving technique may get you 1 or 2 mpg but kills the driving fun. Beyond that my mpg problem is 7 or 8 mpg anyway. Best to drive normally and wait until you get 2,000 or 3,000 miles on the car before dealing with this issue.

Originally posted by msrecant


I agree with you 100%. Driving technique may get you 1 or 2 mpg but kills the driving fun. Beyond that my mpg problem is 7 or 8 mpg anyway. Best to drive normally and wait until you get 2,000 or 3,000 miles on the car before dealing with this issue.

One other question for someone more knowledgeable than I. Someone said before the ECU "learns" your driving habits when it's new and adjusts accordingly. So, if you are following these screwball techniques is the car also learning bad habits? And if so, when you revert to some normal driving techniques wouldn't this put the ECU all miscalibrated for "normal" driving? Just wondering, but it seems like you might be making things worse doing this.

Here's a question: I often do a lot of short trips, 20 minutes or less, and when I do, I can watch the gas gauge move. Yesterday, I actually made a couple longer trips, 40 miles one direction, a two minute stop and 75 miles in the opposite direction. On the longer trip with the car all warmed up and averaging close to 85 MPG with sprints to triple-digits through Camp Pendleton (for those who know SoCal), the gas gauge barely moved. Of course, when I did fill up before my return trip I still got less than 16 MPG....thank goodness for those long highway trips at the end of the tank though or I might have had my worst mileage ever!

Oh, so back to my question. Many people citing their mileage have talked about the highway/city mix of driving, I am wondering if those getting higher mileage aren't also driving a warmed-up car (independent of whether it's city or highway)?

Care to comment?

P.S. Canzoomer, you mentioned "hoping" to get better mileage...does that imply you are keeping the car?

Here's a question: I often do a lot of short trips, 20 minutes or less, and when I do, I can watch the gas gauge move. Yesterday, I actually made a couple longer trips, 40 miles one direction, a two minute stop and 75 miles in the opposite direction. On the longer trip with the car all warmed up and averaging close to 85 MPG with sprints to triple-digits through Camp Pendleton (for those who know SoCal), the gas gauge barely moved. Of course, when I did fill up before my return trip I still got less than 16 MPG....thank goodness for those long highway trips at the end of the tank though or I might have had my worst mileage ever!

Oh, so back to my question. Many people citing their mileage have talked about the highway/city mix of driving, I am wondering if those getting higher mileage aren't also driving a warmed-up car (independent of whether it's city or highway)?

Care to comment?

P.S. Canzoomer, you mentioned "hoping" to get better mileage...does that imply you are keeping the car?

Originally posted by silver8
P.S. Canzoomer, you mentioned "hoping" to get better mileage...does that imply you are keeping the car?

Well, if you read in the Canadian section threads, you will see I am involved in an engine computer, ECU over-ride project..

If this pans out as decent I will then be keeping my car..

It finally reached the point where I decided I am willing to spend some of my money to fund the project, find the people with the resurces to do it, etc..

Talk is cheap. Until I have results to show, it is all speculation.
I may have to return the car before finishing, but I know others who are keeping theirs and who are willing to help, so even if I return it I may buy another afterwards.

I was offered a GT6 with roof and NAV yesterday at MSRP with no roof or NAV..

Things are getting better..

Canz: in fact, while sitting on a conference call here I looked at the Canadien Dyno thread and saw your input there, so I do see your efforts. Good redemption on your part (not that you needed it!).

I got my title in the mail two days ago. I am strongly considering returning the car, but haven't identified exactly what I would replace it with. I am running out of time though. Having traded in my last car on the 8, I need something. Mazda, your efforts or someone elses may well address the shortcomings, but I won't be in a position, should I take the buy-back offer, to wait that out. If I get another car, it will be with the goal of keeping it 4 to 6 years. If there were a late-model M3 I could get for under US$40K, I could well be set for that 4 to 6 years. Though, I haven't found many priced at that point and even if I do, that represents an $8K premium over the 8. You can buy a lot of gas for 8K!

Good luck in your efforts, I will keep an eye out...whether I keep the 8 or not.

I am still looking at the options too.
I have a TT lined up, but the guy has to find his new car, and of course i have to get the cheque from Mazda.

Looked at the Acura CL Type S coupe with 6 speed yesterday.
http://www.acura.ca/AcuraEng/Models/CL/Specifications

I can get one for exactly what I would get back from Mazda for my 8.

Nice car. Nicely appointed.
Lots of power and features.
Bit heavier (1592kg/3500 lbs)

And it is built by Honda. I have had VERY good experiences with Honda cars and delaers. Parts prices and aftermarket are inexpensive and well provisioned.

Still, if the RX-8 can be fixed, I will probably keep it..

And if not, well, I am still liking the TT, but can only afford a 2 year old one with warranty extensions.
If I want new, then the Acura is pretty attractive..

As for the gas, let's do some math:
As I am buying premium 91 octane now for $.84 per litre, and at around 16l/100 versus 11l/100 it is costing me an extra 5l/100 at $0.84, and if I drive 15,000 kilomteres a year:
5 l x 15000/100 = 750 liters
750 @ $.84 = $630 per year.
So, over 3 years I would be paying an extra $1,890 for gas as compared to the TT or Acura.

Not a HUGE number, but it adds up.
Enough to pay for extras, like accessories and car toys..
Plus with the RX-8 I am about to have to drop around $1800 on wheels and winter tires.
Neither of the other 2 need that. The Acura comes with all weather radials, and the TT with spare wheels, winter tires and Quattro.

So, over 3 years the price for keeping my RX-8 is about an extra $3,700
And if I pay for mods to make the power and maybe some mileage about $2000, although i will get a bit of that back on gas savings..

Hmmm, arithmatic. I like donuts better..

Well canzoomer has taken a lot of heat on this forum and I appreciate his comments good or bad. I have sent in my papers to return the car. I don't think this issue is going to be resolved before the deadline but there is always another one out there if it is. I just hit 1400 miles on mine and got 13.2 mpg on my last tank of 89 octane. No I am not a lead foot. As I have said before there is too much disparity in MPG users are getting to be chalked up to lead feet or break in theories. I sure hope these issues are resolved, I would like to consider buying another 8 later.;)

[QUOTE]Originally posted by canzoomer
[Not a HUGE number, but it adds up.

I agree. I came up with (and posted elsewhere) a similar number (around US$600 per year) comparing the 8 to a 330 based on 13,000 miles per year. The other calculation I added to that post (too lazy to go find it) was the time spent thinking about and/or actually getting the gas. It's a little early in the morning for heavy calculus, but looking at your numbers, I would guess your tank capacity at about 48 litres, based solely on your 16l/100 and my getting about 200 miles between fillups. That means that at 15K klicks per year, you are going to the gas station 50 friggin' times per year!

Why couldn't Mazda at least engineer the car with a bigger gas tank? I would be that most cars averaging 15 MPG have at least 20 gallon tanks.

Last tank i did a highway run, but paid attention to keeping rpm below 4000. This is 126kmh in 6th.

I got around 13.4l/100km or 17.6mpg
I looked in the RX-8 book tonight, and found the first intake switch happens at 3750 where it goes from 2 to 4 runner.
I bet that if one kept below 3750 one could easily hit 20mpg.

Of course that is 115kmh (71mph)

Booooorrrring!!

Originally posted by silver8
Why couldn't Mazda at least engineer the car with a bigger gas tank? I would be that most cars averaging 15 MPG have at least 20 gallon tanks. [/B]2004 Audi S4 - rated MPG 15/21, gas tank 17.3 gallons.

That means if you fill up at 1/2 tank you get to fill up every 130 miles or so.

Sound familiar?

Yes, it sounds too familiar

Originally posted by canzoomer
Last tank i did a highway run, but paid attention to keeping rpm below 4000. This is 126kmh in 6th.

I got around 13.4l/100km or 17.6mpg
I looked in the RX-8 book tonight, and found the first intake switch happens at 3750 where it goes from 2 to 4 runner.
I bet that if one kept below 3750 one could easily hit 20mpg.

Of course that is 115kmh (71mph)

Booooorrrring!!

I wish the gearing in 6th was such that we could go up to 80 without the intake switch. Typical highway speed where I live is about 75. I'll bet we would see some better MPG numbers from a lot of people.

""2004 Audi S4 - rated MPG 15/21, gas tank 17.3 gallons.

That means if you fill up at 1/2 tank you get to fill up every 130 miles or so.

Sound familiar?""

Ah doesn't the Audi have over 300HP also? A little bit of a difference I think.

I am awaiting a copy of the California "title printout" from the leinholder so that I can send all of the paperwork in on the buyback.

Meantime, at 1800 miles, here's what I am seeing wrt MPG:

Certainly NO IMPROVEMENT WHATSOEVER. if anything, its getting worse. My 8 rarely does better than 13ish MPG; last tank was 12ish MPG. I use the "ish" convention because I don't have my notepad in front of me, and besides, it really doesn't matter, considering the despicable fuel economy levels I am seeing.

My opinions of the RX-8 remain unchanged: Its a solid car, built with precision engineering & high quality. The handling is top-notch. However, something has gone HORRIBLY wrong with the ECU tuning, and unfortunately, Mazda remains hunkered down in silence. Many people still oogle & ask me about my car; When I tell them how bad the mileage is, they always recoil in horror. I am quite sure they won't be buyers & they will slowly spread the word. GOOD. Maybe Mazda will eventually get the point that they HAVE TO ADDRESS THIS PROBLEM or their sales will suffer.

I dont know if you reed this thread but a lot of people started getting better mileage at 2000 and your at 1800

Yes, some do. And some don't.
For example I managed to get better mileage on a tank recently, by driving very carefully always below 4,000rpm.
And even then I got around 18mpg.
I have 3600km on the car ( that's 2,236miles for Americans)

Originally posted by poison123
Ah doesn't the Audi have over 300HP also? A little bit of a difference I think. The original poster simply said "most cars that get 15 MPG have over 20 gallon tanks." The 2004 S4, regardless of its HP, shows that even some newer cars don't.

Originally posted by canzoomer
Yes, some do. And some don't.
For example I managed to get better mileage on a tank recently, by driving very carefully always below 4,000rpm.
And even then I got around 18mpg.
I have 3600km on the car ( that's 2,236miles for Americans)

I would bet a Toyota Prius has as much oomph as the 8 does if you keep the latter below 4K. In fact, it seems incongruent to be so obsessed with maximizing mileage in a sporting car. Now, I have read articles about people trying to get the best possible mileage out of a Prius or the Honda Hybrid, but that is a completely different sort of car.

Yes, I think I am submitting my paperwork tomorrow. I just hope I can find a used M3 at an acceptable price. I am still a little resistant to spending that kind of dough on a car, but my wife is doing her all to talk me in to it...what's a guy supposed to do?

Originally posted by Genom
I have noticed that even with conservative driving the first half seems to go faster than the second half, although I have no idea why. [/B]

With my previous car (Firebird) it was much worse. Someone explained me that the fuel tank in the firebird is not cylinder or cubic shaped, but more like a triangle.

It's wider at the top than at the bottom.

The Firebird's display tells you how high the tank is filled. So if it was filled to half height, that meant you had 6 out of 16 Gallons.

Maybe it's similar with the RX-8.



My dealer gave me a first fill-up with the car and I got 17.3 MPG out of it. Turned out that they only have 87 Octane gas.

I drove mostly between 3500 and 4000 rpm, but a few times hitting 6000 rpm and once >8500 (I got to hear the beep)


If everyone measures exactly, maybe it has to do with how 'early' the model is? I got mine 9/16/, no idea when it was built. Can that be told from the VIN?

-Peter

woohoo.. i got 18.4mpg on the 8. Its only been my 5th tank. =-]

Being my first post here, i think i should attempt to clear some things up.

I've owned 2 rotary vehicles and worked on many with friends. Gas mileage has never been a rotary strong point. If you bought the car for gas mileage.. you bought the wrong car.

Now my guess is Mazda richened up the fuel maps to over compensate for all the blown FD3S engines. Mazda/Ford doesn't want a repeat of the 3rd generation RX7. So, the loss of HP is happening because of richening up the maps. Guarantee, you lean it up, it will make more power but at the expense of engine life. Mazda is working hard to get the Rotary back on the streets, and I for one would like to see another RX7 in the near future.

My tip to you all, if you want better gas mileage is in fact to drive the car harder. I think that if you all bring the car up to 4500-5000rpms every shift that you will actually see better gas mileage. If you shift at 3k you are making the engine work harder, since its not in its torque band to lug your car down the street. Every Rotary i've owned i've always taken to 4.5K then shifted, i've always seen better gas mileage that way. Also note your throttle input, how much gas are you giving it? The faster you get the car up to speed, the less it has to work. It might seem counter-intuitive, but everything on rotaries is. If you don't agree, then don't, i'm basing what i know off of dealing with these cars for years.

I don't know for sure if Mazda has a "break-in" map for that car wired into the ECU? It might be running rich for the first 2000-3000 miles just to compensate for break-in.

When I rebuilt my FD's engine, we set the maps on the PFC extremely rich to eliminate any chance of detonation. If your car is having a lot of carbon deposits, its running too rich. Mazda should be able to reflash the ECU to fix that.

Anways, just my advice. I really like the RX8 after driving a local owner's. After i sell my 7, i plan to stick with the rotary and own an 8. Good luck to you all out there! Let me know if my advice helps any.

:D

Thanks for the practical perspective and advice. Good to hear, since I mailed in my "I'm keeping it" letter this morning. Never seriously in doubt despite the mpg angst.

As has been noted in another threat, carbon soot does collect at bottom tip of each exhaust. Seems consistent with your observation.

New wonder: will keeping the DSC/TC off, as has been put forward to increase performance and possibly help mileage, extend any "learning curve" or break-in period programmed into the ECU? Would help to have some electronic rather than observation data, but at this stage it would seem the only ones who have it are Mazda, and (being a lawyer) I can understand why they ain't saying. Maybe if folks started chatting this up with service depts. on their visits we can find out if they have been given a clue.

Originally posted by 7Neverdies

My tip to you all, if you want better gas mileage is in fact to drive the car harder. I think that if you all bring the car up to 4500-5000rpms every shift that you will actually see better gas mileage.
:D

I did that for a while

I got around 14 to 15l/100 ( 16 to 17mpg) while driving hard on the highway. By hard I mean 160kmh+ or around 5,000rpm.

In the city, driving hard I got 18-19l/100 (12-13mpg)

So, I decided to see if it is POSSIBLE on my car to get better than 18mpg.
So, I did the run at sub 4000rpm and WAS able to get just over 18mpg.

Other RX-s dont matter much as a comparison, IMHO.
On the Renesis we have there are 3 pairs of intake runners.
One runs 0 to 3750rpm, the second cuts in there, and at 7300rpm the 3rd pair cuts in.

Adn it seems very much like our fuel mileage is tied pretty predictably to how many intake runners gives you what mileage.

Again, as has been mentioned, ECU settings are likely the culprit.
Until we test with JSpec ECU maps, or other modded ones with leaner burn on higher RPMs we will not know with any certainty.

Canz, you are the man: "Until we test with JSpec ECU maps, or other modded ones with leaner burn on higher RPMs we will not know with any certainty."


One question--are JDM cars getting the black soot on the tail pipes that we are getting here? It seems that the ECU programming that runs the car rich to "protect" the engine (as some speculate) would not be unique to the US cars. Of course, that says nothing of the programming (unfortunately apparently for us with the State-side smog-regs) designed to extend the CAT life.

Just wondering...my mileage and possible the performance too seems to be creeping up as I approach 2K miles on the odo. Though I have done a couple of long stretches (40+ miles) on the highway lately. Not without some second guessing, I sent my info for the buy back yesterday. But, as I still own, drive and appreciate much about the 8, I'm no troll...yet!

On that note, after dropping the paperwork at the Post Office to get the return receipt on my letter, I switched the DSC off (not all the way off) and proceeded to rip around a couple of corners (35+ MPH) and loved the tail hanging out!!! Of course, that made me want to run back to the post office. But, if all the stars allign and I get the next car I have in mind, I will hopefully not miss the 8.........................too much.

Thanks Silver8, it is good to know with certainty my gender!]

As for the soot: "Dunno"

I mentioned this because I read aout some people getting better mileage, but I am suspicious. Some people drive low rpm by habit, and probably are gettting much better mileage than me.
I don't "drive it like I stole it", but I do like to drive fairly hard.
When I test drive cars at dealers the salesmen comment on the way I drive. Some say nice things, some say littel , and I once had a guy say "Eeep" when I drifted around a corner, but overall I admit to some "play".

If I meant to "drive at 55" I would have bought a Prius.

And, if I wanted to get 12 mpg I would have bought a Mustang Cobra..

Surely there should be a place in between those two?

Anyway, more electronics play and dynoing this Saturday. We will start to apply some different settings on our little ECU over-ride wedge experiment and see what it runs like.

In any case I hope to have some news come the end of the weekend.. Not sure just what yet, but time will tell.

Thanks for practical experience gained from driving and working on rotaries. The problem is, they were not RENESIS rotaries. Here's the engine designer talking, in a book Mazda published: The side-exhaust engine was an entirely new design, with new components. To us, it was as new as the first NSU-built prototypes.... And so were the problems and challenges with the new design, which were as numerous as they were unforeseen.
IMO, some lessons learned from previous models may still apply; others won't.
As for setting straight those of us who are disappointed with our gas mileage, I'm afraid you drove right off the road on that subject. We're not dimwits. We knew pre-RENESIS gas mileage was low. So did Mazda. Their book explains that Ford would not have allowed them to build the RX8 if Mazda hadn't proved it would be much better. And it was. The EPA-certified engine got 18-24 (25 for auto, which has lower revs and is higher geared). So we are not fools expecting more than we should have from old design engines. We're otherwise smart folks who trusted Mazda to deliver engines like the pre-production RENISIS, engines that perform up to spec. We bought the right car, but Mazda didn't deliver it. I'm still hoping that we can get Mazda to make our engines, as well as new production, do what they are designed to do.
What's baffling, and frustrating, is that Mazda won't tell us what went wrong. They knew all about durability concerns when they finalized design on engines that made 247/207 hp and good mileage. Why did they sell us ones that don't? My guess is that production quality, especially on seals, fell short. Mazda's book explains that the new, better seals allow higher pressures, bringing more power and better economy. But I'm just guessing.

Mitch

Watch out! I hear the "Yay Birds" coming..

They will vilify you and write bad poetry about you, and if you are VERY lucky they will start threads about you.

Please be gentle, their feelings are easily hurt.

I've been getting 14 MPG consistantly in LA city driving. The only exception has been a 90 mile round trip with all freeway miles. For this non-stop I finally got 19 MPG.
I have 1800 on my 8.
The last full fill-up jumped to 16 MPG and all of my standard city driving.
Maybe there is something to the rumor of MPG improvement as you approach 2K.
I stopped using premium after my second $28 fill up. Regular unleaded seems to be fine.
I am keeping my 8.

Originally posted by Mitch Strickler
We're not dimwits.....

Well said!

None of us bought the RX-8 expecting 30 MPG from a rotary or crystal clear exhaust from an engine that, by design, burns oil. Nor did we expect a Version 1.0 car to be bug free.

What is frustrating is that Mazda isn't saying anything at all on the low MPG and low dyno testing issues, which are much more than simple V1.0 bugs. It is like we are too stupid or too unimportant to deserve an explanation of even what the problem is.

Kind of like if Microsoft built cars ......

Yeah - its a shame when people jump on & pop out post #1 without so much as doing their homework.....

Anyways, my RX-8s 12-13MPG saga continues, unwavering - narry an improvement as I approach 2k miles. I have a sinking feeling 2k is gonna blow right by without any change. If, for some reason things get better, I'll certainly let y'all know.

On another note, I wanted to mention a question that MNAO asked me during the course of the initial buyback call I made to them. Others may have gotten the same question: "Why are you returning the car?" Of course I said the mileage was worse than a Ford Expedition - approaching that of an RV. Then, she asked: "What kind of mileage are you getting?" I told her. Then: "Have you asked your dealer about it?" Of course, I have asked the dealer & of course, they have no clue, so I told her that, too. I bet if we could get our hands on the % of people returning due to bad MPG, it would be the #1 reason. Of course, MNAO would be horrified if the buying public found that out.

Originally posted by astrlsrfr


On another note, I wanted to mention a question that MNAO asked me during the course of the initial buyback call I made to them. Others may have gotten the same question: "Why are you returning the car?" Of course I said the mileage was worse than a Ford Expedition - approaching that of an RV. Then, she asked: "What kind of mileage are you getting?" I told her. Then: "Have you asked your dealer about it?" Of course, I have asked the dealer & of course, they have no clue, so I told her that, too. I bet if we could get our hands on the % of people returning due to bad MPG, it would be the #1 reason.

I agree that to many/most people, the mpg issue is more important than hp. I read in another post a couple weeks ago here, MNAO had told someone "Some buyers have mentioned the mpg issue but we've received no complaints." Sounds like a real smokescreen to me.

I called their helpline yesterday. I'm keeping the car but I "officially" complained about the mpg. They did not ask me about it, but I brought it up myself. I have no idea if they are doing anything with my complaint; I asked the guy about that and he said a record of my comments was made. I got the impression he meant in my customer file, but hopefully they have a database of complaints they are compiling and this should be a key one. Has anyone else complained to MNAO about mileage?

You have to make noise about it, a lot of noise. Car companies tend to be hard of hearing. We've all heard the "We've haven't had any complaints about this... You are the first one..." before.

The MazdaSpeed Protege owners were having problems with hesitation and other fuel related issues with their cars. They kept making noise and contacting people at Mazda and now they are getting a reflash that not only seems to have fixed their problems, but they ended up now with a nice power and torque boost. It helped that some Mazda employees owned the car and experienced the problem thenselves, but the involvement and the noise and calling the right people, not just customer service, is what did it.

my mpg was around 12 and it sounds crazy but others will agree once I hit 2k my mpg has approved to 18-19
As far as making noise--I would be

So far I have put gas in twice since getting my RX-8 last week. The first time I filled up (Citgo 91 octane), drove 131.1 miles and it took 8.6 gallans= 15.24 mpg. I then drove 126.4 miles and it took 6.3 gallons = 20.06 mpg. 90% of my driving is stop and go in the Tampa Bay area of Florida. The A/C is on all the time, The DSC has been turned off, except for 30 miles while it was raining. The car has less than 400 miles on it so it is not yet broken in and I have not gone over 6k rpms. I do not drive it like an old lady either. My previous car was a Celica GT-S and it had less torque than the '8' so perhaps I have been conditioned to drive differently, thus getting good mpg? (ps I averaged 27 mpg in the Celica)

Well, I'm happy to report that I finally achieved the 24 MPG (as advertised) in highway driving. In fact I did it on 2 tanks of gas on a trip to Virginia. It possibly could have been better, except that road construction put traffic at a standstill for some time.

I have about 5,200 miles on my car now and I have gotten between 18 and 24 mpg on every tank (except on my track days at VIR which averaged 11.5 mpg). None of my driving involves a lot of city driving, though, which helps quite a bit.

Originally posted by Kurt Bob
Well, I'm happy to report that I finally achieved the 24 MPG (as advertised) in highway driving. In fact I did it on 2 tanks of gas on a trip to Virginia. It possibly could have been better, except that road construction put traffic at a standstill for some time.


Way to go, Kurt. I've been getting around 18 mpg since going over 2000 miles (I'm at 3800 now). any hiway driving is still pretty short-range around the San Diego area. Then I took a trip to LA and back and got 20.4 mpg; 80 percent hiway mostly with a/c running. Maybe that's the best I'll ever get; i dunno.

I can tell right now the tank I'm on is going to be maybe the worst ever and I don't know why. This is my first tank since the LA trip and I'm barely gonna get 200 miles before hitting E. I normally get 220 miles per tank; 240 on a good tank; 270 on the LA trip. Why would it suddenly plummet like that? No freakin' idea.

(BTW, I properly set the odometer and measure gallons at fillup to calculate mpg. I'm just using the mpt as a broad comparison.)

17.1 MPG. Just went over 3000 miles on this current tank.

Ive got 4300 miles and I hit 20mpg this tank

22mpg last tank, mostly highway, dsc/tcs on, several (6 - 8) sprints to 90 mph.. one to 110, and about 5 redline runs in 1st and 2nd.

900 miles on the car so far.. redlines were the ceremonial i just passed the 600 mile break in. :)

A/C was on half the time, and the car pulls very very well. (seemingly better every day than the day before)

Oh yeah.. I'm running premium gas.

Couple of ideas: RPM vs mileage. I've noticed in my 7 that I get worse mileage if I lug the car in a lower gear vs. rev it. Seems that mileage is more related to throttle position (when the secondaries open). Just throwing out a theory - the ECU probably runs richer when you lug it to avoid detonation.

Second: Can the ECU be reset? On a '7' the ECU 'learns' as time goes on and may not be accounting for your now changed driving style. On a 7 you disconnect the battery and press the brake down for 5s to reset it. Very noticeable when this is done as performance drops dramatically until it 'learns' again. Does anyone have an 8 shop manual to determine how to reset the ECU?

I thought you just disconnect negative on battery for ten minutes to reset ecu

Originally posted by mikeb
I thought you just disconnect negative on battery for ten minutes to reset ecu

That works too. Done it several times:D

What's guy, i'm getting the same out come with my 8. normal driving back and to from work. i travel about 15 miles a day and have to put gas in every 3rd day. so, yes the gas mileage sucks, but i still love the car. i traded my 91 300zx n/a for it. not totaly happy!

Hello all,

Wow 160 some replys on this topic, maybe there is a problem :)

Im getting about 14 MPG or less with about 600 miles on the car, i'm filling up every other day with 91 Octane. The problem HAS to be a mixture problem because not only is the exhaust tips BLACK the whole back of my car is coated every day with a layer of black soot. Yes they(mazda) says the car will run rich durring breakin but good god i'v must have at least 4-5 MPG of lost economy on the back of my car every day. The question is to all you 20+ people do you have the same soot problem? My soot covers from the trunk/window meeting back. I dont know if this PIG rich mixture is normal for rotery breakin but it just seems to be a bit much to me.

Keep this post going lets find a solution to this problem, no reason to get rid of this beautiful car :)

T o n Y

Tony, you've sure got the soot bad. I get it on the tailpipes immediately after washing I see new accumulation. But not all over the back of the car... holy smoke (so to speak!) I been getting around 17 mpg locally hiway/city; i think my current tank close to 15 but I'm due for fillup now to double check. We do have to figger this out and I'm sure there's a fix but we gotta get mazda's attention and help and right now they're keeping their head in the sand. Very discouraging. If not for that, I rate this car a 10 but I hate the crappy mpg.

I haven't used a calculator, but a quick crunch in my head says I'm getting about 10mph. I'll be honest though, I didn't get the car to ease up to speed from a light. I've been driving it like it's been begging to be driven.

I wish the milage was better. But whatever. Iraq needs to kick up some thanks soon anyway.

I got my 8 (6speed) 5 days ago, boy this baby eats fuel like a pig on a mission. Here's a ballpark figure, 17gl / 360 miles = 21.1 MPG. But 85% of them are highway. I hardly push RMP over 5k...just imagine what kinda MPG will I get if I was gonna have some fun with this baby. I guess 8 is like a high maintenance girlfriend, she's SEXY, she's HOT, She's FAST...but you need money to keep her around!!

Here's an interesting statement from the window sticker,
Results reported to EPA indicate that the majority of vehicles with these estimates will achieve between 15 and 21 mpg in the city, and between 20 and 28 mpg on the highway 28? Has anyone came close to 24mpg?

It's a bad idea to run the tank to near empty level. Car manufacturers recommended to refill the tank when it's down to 1/4 tank. This way, less deposits would get into your engine. Just a FYI.

I thought you guys would get a charge out of this.

Went to the Mazda dealer to get my oil changed. They ended up putting 10W30 in it because they said the couldn't find any 5W20 (what BS but that's a story for a different topic).

When I mentioned to the service writer that MPG seemed low, he made a note of it for the tech to check out. Here's what the service tech wrote on my service ticket:

"S17-Fuel trims OK....No codes stored in system...all tire pressures OK....customer should keep RPMs under 3,500 for better fuel economy"

Under 3,500 RPMs? Hell, I'd be passed by every granny on the interstate that's driving a Crown Vic if I kept it under 3,500 RPMs.

My service tech is a "maroon".

"Customer should keep RX-8 parked in driveway for maximum fuel economy."

Originally posted by jem777
"Customer should keep RX-8 parked in driveway for maximum fuel economy."

LOL! Better yet, only drive it in reverse.

Originally posted by graphicguy
"S17-Fuel trims OK....No codes stored in system...all tire pressures OK....customer should keep RPMs under 3,500 for better fuel economy"


If nothing shows up in the tech manual fault-tree, then you (and I)obviously don't have a problem.

I am getting 185- 200 miles per 'tank' (when light comes on, refill and reset odometer). I drive pretty conservatively (most of the time).

I have only 1600 miles on the car, but last fill-up I got 19.4 mpg. Mostly in town driving and I don't adhere to any particular rpm driving range. If I feel like, and road conditions allow, the foot is in the gas.

That really is not that bad. I mean, my '93 Protege gets about 23mpg city. My WRX gets 19mpg city also.

Ok I noticed something interesting:

Brand of gas seems to make a difference in gas mileage.

WAWA (Regular) - 20-21 MPG
Mobil (Regular) - 16-18 MPG
Exxon (Regular) - 18-20 MPG

WAWA (Premium) - 19-20 MPG
Mobil (Premium) - 16-18 MPG

I'm not sure what to make of this infomation I have gathered except I go to WAWA and get Regular if I want my tank to last. BTW, I run it to 6k on most shifts and I don't baby it. I also have 1640 miles on the car.

Lets see if we can slowly but surely figure it out.

hmm keep RPMs under 3,500 ?!

Sounds like that tech needs to talk to the product manager.

At the Sevenstock banquet the Rx-8 product Manager (who happens to read this forum) said that this was not neccessary. He suggested that we just drive the car not worry about RPMs and the fuel economy will be inline with their tests. It's kind of strange that a tech would suggest this.

I don't want to misquote him, so if somebody has a video clip of him addressing horsepower and gas mileage could you post a link? Or better yet if you are reading could you chime in? I apologize that I forgot your name and it's not listed on the sevenstock site anymore :(

I posted a while back, but now that my 8 has 2400mi on it I can give an updated comparison of same drive(all hwy 130mi each way), same driving styles
87 Rx-7 turbo : 21mpg
04 rx-8 tour: 15mpg

This is my first rotary engined car and I knew that rotaries are not the most fuel efficient motors around. My issue is with the range between fill ups. I am getting only 210 miles between fill ups.

Mazda should have put in a larger gas tank in the RX-8 so that one can get about 300 miles between fill ups.

I just hit 2000 miles and things have started to change.

First 1800 miles - 13.8 mpg

Last 200 miles - 15 mpg
(1800 to 2000)

Mine is an early build US RX-8 (May 2003).

My mileage is almost all in-town stop-and-go driving. I have tried a variety of driving modes (DCS/TCS on and off) and driving styles (from Grandma to Evil Knevil) with little mpg variation. I consistently use Texaco.

At least I finally made it to the bottom of the scale.

Originally posted by msrecant
I just hit 2000 miles and things have started to change.

First 1800 miles - 13.8 mpg

Last 200 miles - 15 mpg
(1800 to 2000)

Mine is an early build US RX-8 (May 2003).

My mileage is almost all in-town stop-and-go driving. I have tried a variety of driving modes (DCS/TCS on and off) and driving styles (from Grandma to Evil Knevil) with little mpg variation. I consistently use Texaco.

At least I finally made it to the bottom of the scale.

Congrats for getting this far. Your pattern sounds a lot like mine; early build and improvement after 2K. I average around 17 mpg now. As you say, it seems to have little to do with how I drive. I have tried every strategy suggested on this forum, kept good records, and see no correlation between octane/driving habits/mileage. I am up to 3700 miles now with about 60/40 city/hiway.

I-95, D.C. to Richmond and back, 21.2 MPG on Shell 93 Octane, about 1500 mi. on car built late May. Local commute mileage has crept up to 14.75. 6SPD GT.

Originally posted by miata2rx8
I am getting 185- 200 miles per 'tank' (when light comes on, refill and reset odometer). I drive pretty conservatively (most of the time).


Mine is similar, with about 450 miles on the Odometer. I didn't buy the car for fuel economy, but this does indeed seem pretty low. Also, I drive mixed - from conservative to pretty heavy footed. Hoping for some improvement with additional miles...

225 a tank for me

i'm begining to worry guys... my car has got some serious problems concerning gas consumption. i get 25% in the city, 15-18% highway, and 30% sporty driving. That's liters/100km. in miles per gallon that would be about 9.4 in the city and....oh you do the math for the others. I'm really scared and I'm from europe. a liter of gas here costs 1.3 dollars. i've used over 5000$ worth of fuel in just 10.000 km and this sucks. apart from that i love the car... wish it were a lot more powerful, but maybe in the next generations.

2 years 4 months has gone by since this thread last had a post. That must be a record. :shocking:

Anyway... All I will tell you is that your results are abnormally low.

In the winter (now) driving with winter tires, 5 miles each way to work, I see 15 MPG. In the summer that same path gets me 17 MPG on 'summer' tires. 100% highway at 75MPH, nets me 21 to 22 MPG.

Temperatures , tires, driving speed (e.g. highway vs. city) and how much time you spend over 4000RPM effect MPG. If you are within reasonable limits on those things and are still seeing less than 13 to 15MPG, have your car serviced.

POOR FUEL ECONOMY

DESCRIPTION


The fuel economy is unsatisfactory.

POSSIBLE CAUSE


*

Contaminated air cleaner element
*

Air suction at intake-air system (between MAF sensor and intake ports)
*

Poor fuel quality
*

Inadequate fuel pressure
*

Pressure regulator (integrated in fuel pump unit) malfunction
*

Fuel pump relay stuck closed
*

Fuel leakage from fuel injector
*

Restriction in exhaust system
*

Erratic signal from eccentric shaft position sensor
*

Improper MAF sensor installation
*

Improper fuel injector control operation (abnormal signals from MAF, ECT, front/rear HO2S and IAT sensors to PCM)
*

Knock sensor malfunction (abnormal signal to PCM)
*

Contaminated MAF sensor
*

Improper engine compression

o

Engine internal malfunction
o

Abnormal engine oil condition (viscosity, deterioration)
o

Low oil pressure
o

Excessive fuel pressure
o

Metering oil pump malfunction

+

Leakage or clogging in oil pipe
+

Leakage or clogging in oil nozzle

POSSIBLE CAUSE

Eccentric shaft bypass valve malfunction (stuck open)
#

Improper cooling fan control system operation
#

Thermostat malfunction (stuck open)
#

Improper engine coolant level
#

Improper ignition timing
#

Weak spark
#

Spark plug malfunction
#

Brake dragging
#

Low tire pressure
#

Clutch slippage (MT)
#

Improper ATF level (AT)
#

Improper A/C operation (A/C cut-off control does not operate)

so what you're saying zoom44 is that we should just give up? :)

I think you're all driving your car poorly.
I've had the car for about 2 years and I get on avg. between 18 and 20 mpg. I floor it once in a while just for fun, but that doesn't do anything. I do way more "city" driving than I do highway.
On a road trip I think the best I got was 22 mpg, but my car was loaded down with stuff.
But for normal every day driving, I just try and keep my rpms low by upshifting.

I have not discussed milage on this car for almost a year and a half. I was involved in a series of threads and spent a great deal of time trying to find out if the mileage of my car could improve.

I get in town about 13 mpg. I have only 15000 miles on the car after two years.

The dealorship did test my car and were able to get an average of 16mpg in town and on the highway.

They were not able to find a solution.

Mazda even shiped my computer to themselves and tested it and shipped it back and they had no comment.

I ownded a car at one point that had a 400 plus cubic inch engine and dynoed at over 500 hp and it got 14mpg

If I granny drive this car I can get 15mpg in town.

If I wanted to drive that way I wouldn't own this car I'd own a Prius.

My conclusion.
The milage will not change. For some reason it gets worse mileage then cars with more Hp. Many claim to get better milage. I am not going to do anything about this. I love the car and would not trade it for any car of costing any where close to it regardless of the mileage or hp. The only car I would trade would be a Porsh costing 60,00 and that is not happening. I will live with this and accept it unless Mazda finds a solution. I am not angry at them They built a wonderful car that has a flaw.
All cars have flaws.