I purchased my RX-8 based on the reviews, comparisons and 3-test drives. I narrowed it down to G35 and RX-8, which I choose RX-8 based on the reviews (like the road & Track comparison) and its unique styling. At that time, I was not aware of the HP issues, which I just found out last Friday. I am a little concern on this issue, but mostly on gas consumption. I know the engines runs rich, but 14-16 mph! Like one of your members said (it is not a SUV). Just wondering if others have the same gas consumption issue, and would mpg get better after 1000 miles or so (I am on 600M). Would greatly appreciate inputs.

I know a lot of people have been reporting MPG issues, but I have no complaints. Through 400 miles of almost strictly city driving, I've managed 18 mpg. That's exactly what Mazda reported.

I have the automatic, and now have 3000 miles on it. So far, I've been getting 19-21 mpg average. Never below 18 mpg.

I borrowed jdl's spreadsheet and created my own mileage log (http://home.socal.rr.com/mozzy/RX8_mpg_log/_RX8_log.html)

I get 15.8mpg over the course of 1463 miles, consuming 92.62 gallons of gasoline..

I average 19MPG in city, 24MPG in highway right now with all of 1830 miles on the car. When running AC constantly it drops to about 17MPG city and 22 highway.

I average 17-18 mpg, mostly highway, but air running alot and some "spirited" driving. (900 miles on car)

With 2400 miles on her, she is giving back to me 21.4 MPG average.

Least = 17mpg
Best = 24 mpg

All the variation in mpg is what's preventing me from finally making a purchase. Will I get a 14mpg RX-8 or a 20mpg RX-8? Unfortunately, Mazda does not consider a 13/14mpg car "defective" and I won't be able to exchange it.

Mazda doesn't consider the mpg issue a problem ... yet. I think there's a real issue here, and it fascinates me that there's such a wild variance of mpg numbers.

My theory is that some cars got a different ECU re-flash than others. There's also the issue of a possible mileage switch that will result in better mpg numbers. Let's wait a little while longer (i.e. a few more thousand miles for some of us) before we declare that Mazda doesn't consider the mpg issue a problem.

For the record, today is my one-month anniversary of owning my '8'! :D Here is my average over that time....

2540 miles driven
111.85 gallons used
22.71 mpg avg

This includes the first tank which was 18.99, by far my worst number. I drive 80/20 highway/city. I've used A/C constantly almost every day. I do not baby the car, but use sixth gear as much as possible when on the highway. And I've used 93 octane Exxon gas the whole time.

EDIT: Just wanted to add that I make a point of running the engine up to at least 8500 RPM at least once every trip.

I'm another 8 owner that's getting decent mileage- 18-19 city, 25-26 highway.

That is great. I wish I could say the same. Doing almost 90% highway, with a steady 74 mph, I am still under 22 (21.7) mpg :(

I am really considering my options :confused:

Has anyone tried to correlate gas mileage with geographic region? I ask this because it seems like (based on my 4 car sample) east coasters and north midwesterners get better mileage than southern californians.

Before you dismiss me as being stupid, hear me out. I'm thinking that perhaps the difference in air temp, humidity, altitude, etc. from the different regions are having an effect on the Renesis. I know these factors affect the performance of "normal" reciprocating engines. Maybe these factors have a greater impact on the rotary?

My other theory is that maybe the side seals (the equivalent of piston rings) on the rotary aren't being manufactured consistently.

I have driven my automatic very conservatively for 1,500 miles -- highway cruising 3,000 and below (often well below), very light pedal city and highway. Best tank, 2/3 highway, almost 19. Worst, city with idling, in hot spell, 15.5. Mixed driving, 16-17, and no real sign of improvement with added miles. I'm in Washington, DC.
I agree with the comment that production shortfalls, probably in seals, probably account for the problem. Mine was an early-order car, made May 26. Although I'm not sure, I suspect that most of the cars reporting decent mileage were made later.
Let's keep pressuring Mazda to tell us more about what's going on. They had to do so on hp, because the dyno is a simple test that can't be evaded. It's harder to pin down economy, but not impossible if you really want to do it, like anything in engineering. (Note: I'm not an engineer.) Surely it would be interesting to have Mazda run the EPA test on a production cars whose owners report bad mileage -- I volunteer! -- and see if on average they make the 18-25 Mazda reported to EPA. Another interesting test, as Mazda's development book says that higher pressures from improved seals are responsible for better RX8 mileage, would be to measure compression on those same production engines.
Mitch

Originally posted by mamccubbin
I know a lot of people have been reporting MPG issues, but I have no complaints. Through 400 miles of almost strictly city driving, I've managed 18 mpg. That's exactly what Mazda reported.

glad you are one of us getting better gas mileage. one minor point that i seem to make over and over- Mazda did not test the cars and report the numbers, the EPA did. Mazda just publishes the numbers on the window sticker and elsewhere like they are supposed to.

have any of you getting lower mpg switched gasolines to see if your mileage improved? try a different brand. also Fredx8
your mileage is within the range and should improve more with time. 74 mph is also @ 3800 rpm, try 70 and see what your mileage is then.

and Mitch Strickler you say you don't have any improvement with more miles. how many miles do you have?

Well, a big load off my mind. The car WENT BACK. I simply got tired of watching the fuel gage move quickly to the empty. There were other issues too, like the loud clunck nose when turning from a park position, the noise from the clutch, and others.

Although, I must admit it is a very nice looking car and a real head-turner. It also drives really well – especially on the winding mountain roads. In a way I am sorry to return it, but I would have been sorrier in near future if I had kept it. The real disappointment was when I drove the same distance (from a red light to a specific marker that I can really push the car w/o the feat of being caught) with the RX-8 and my old V6 172HP and reaching the same speed (90 mph).

It was fun! I would definitely re-consider RX-8 if the performance and the mpg issues are resolved.

Oh yes, I forgot to mention one more thing. As I was driving home from the dealer where I returned the car, saw another red RX-8 on a towing truck going opposite direction of me. Off-course it could have been for many reasons?

Well someone said something about its where u live. Well i think hes right because i live in s.f which is a hilly city that most of you never driven before.Driving on 45º angles would surely scare someone thats not from s.f. Well im trying to say is that I have to keep pushing on the gas to get up the hill than most of you, making my gas mileage CRAP. Also the car is a high rev car which takes in more gas (i think the higher you rev more gas u waste)on the freeway high reving the car like at 5000 to 6000+ will surely drop your gas mileage.So it all depends on your driving

Those of you who say you get 20 MPG or more.
A. Drive like little old ladies.
or
B. Are lying through your teeth.


And stownz, never below 18?
What do you coast downhill until you can put the car in 6th gear?

I am one of those whose average was about 13.5 mpg. I drive pure city the whole time. However, this weeked took the car to Key West and got 25.5 mpg, AC was on the whole way. Averaged 3k in RPM cylce most of the trip except when passing when I redlined several times. This was the best mileage I have yet ot see.

I hve just a little over 1200 miles on the car and am approaching 2 months with it. I will attempt to experiment with the city driving to see how I can approve my MPG.

I usually get around 17 mpg, sometimes 16.5, sometimes 18.2...but today was my personal best. I noticed 215 on the trip meter and gauge showed 1/4 full. I usually retank at 180 or so. I filled with just over 11 gallons, and netted 19.36 mpg. I have almost 3800 miles on the car,

so far im at 180 miles on my first tank of gas... with 1/4th a gas tank left. how am i doing ?:P

Originally posted by Pulsr
so far im at 180 miles on my first tank of gas... with 1/4th a gas tank left. how am i doing ?:P

That should work out to be about 17-18. Of course, you'll want to actually divide your miles by how much gas it takes to fill it to get an accurate number.

I have the auto-tran. I got 20.7 with a/c on on my first tank about 80% hwy driving. The second tank I got 23.0 no a/c about 95% hwy driving. The third I saw 22.3 a/c was on the whole time and I was reving it more(Had Fun)! I think I will see 25mpg later!

I am hoping to see an improvement in the CITY mpg. I have stopped using the tip-tronic shifting on my auto to see if this improves my mileage. The joke is the wife will not go on any more road trips in the RX-8. She claims I drive to aggressive. Pretty funny since I am in law enforcement and typically do not exceed the posted by more the 10 mph. On occasion I have let the car out with he in in it.

On the highway trip I think I had it up to 90 once for a 1/4 of a mile.

how do you find out your mpg?all of you seem to know exactly what the car uses. My friends Z car has a gauge(the middle gauge) that tells you how much gas you use.Does the Rx-8 have that too that i dont know of?

When you fill your tank, the pump tells you how much gas went in. Provided you always fill the tank to the "first stop". you can get a pretty accurate measurement by dividing your trip meter by the fuel quantity.

I have 4200 miles and I just got 20mpg for first time

I guess this would be relevent for this thread also, thus I'm sort of cross-posting from another thread regarding disabling TSC (which made no difference, btw):

8/12 - 10/1
- Miles driven: 3,482 miles.
- Fuel used: 213.476 gallons (mostly 87-octane)
- Total cost: $434.10
- Average MPG: 16.31


My mileage log (http://home.socal.rr.com/mozzy/RX8_mpg_log/RX8_log.htm).

I've read all of your comment and I'm still at the same question.

Are you guys driving slow to get this type of mileage?
What is it in kilometers?

squidward
nice log
great info

The gas mileage I posted was mostly 70 to 80 mph. I have not done a tank mostly city driving yet but I bet it will be in the mid teens. I'll post it when I do. I had a RX7 toubo II years ago and did 55 mph (when it was the limit) and got 29mpg. It was a boar and hard to do but I just wanted once to see what it could get max. That was the best I got on any of my Rotaries.

Originally posted by mikeb
I have 4200 miles and I just got 20mpg for first time

mike whats your city/highway ratio? has it changed recently?

Coming up on 3k miles and just turned 20.2 MPG and improving. Plan on disabling DSC/TCS in dry times after mileage stabilizes to see the effect. Would really appreciate getting 24+. Won't mind a reflashed ECU to get there even at the cost of some HP (thus my username).

Most drives are 45 mi each way commutes and try to stay at 75-85 MPH. Have owned 3 RX-7s before, so know you can "idle" drive at 20-25 MPH in 6th while in stalled traffic to up the MPG. I use the CC to control speed to ensure no over stressing of the motor. Rev to 9k at least once/week when a clear road presents itself.

This is the greatest RX- yet!

I drive 60 miles a day
40 hwy / 20 city

Originally posted by mikeb
...40 hwy / 20 city For a second there I thought you were saying that you were getting 40 mpg hwy and 20 mpg city.

duh!:confused:

OK, I didn't want to take the effort of reading this whole post, but I think people need to learn how to read. The sticker on the car doesn't state that the RX-8 WILL get 18-24, what it states is that similar vehicles got an average of 18 MPG in the city and 24 MPG highway. The car is getting exactly the gas mileage it is supposed to. Stop your whining. Either get the car cause it kicks ass and you don't care about gas mileage or shut up and go buy a Civic.

I know this has been stated before, but I thought it should be brought up again. Don't believe me? Go check out the sticker.

BTW, I get between 15-19 MPG. I drive it hard, I drive it fast, and I whip the tail around when no one is looking. You own a kick ass sports car, act like it.

i got 240 mpg before i filled up and i added 13 gallons.. im getting 18 mpg? not to shabby if you ask me :)

ninet4


good POINTS

I've found that if you drive the car below 3700 rpms, the car gives great milege (for a sports car) but rev the thing up to redline too much and you get 14 to 16 MPG.

I've try keeping the Rx8 on the low rpms, but every time I do this I fell like a losser and start downshifting to hear that lovely engine sing.

Guess it was a good idea not to trade-in my 30+ MPG Honda Civic :D

I purchased my rx-8 on Aug 28th. I have about 1000 miles on it now. I got 13 mpg on the first few tank fulls. I am now getting 16mpg. I drive a mixture of freeway and city driving. I am very upset with the mileage so far. I also have the "thunk" noise going from reverse to forward when I start out in the morning. I have the standard transmission and it is VERY noisey. Tons of gear noise when it is idling in neutral with clutch engaged.

My MPG has been a steady 14 for the first 1800 miles. The last two fills have improved to 16 MPG. All my driving has been city.
I am encouraged by the recent improvement and I hope to reach the 20+ figures I have seen on the Forum.
I really expected the promise of 18 as an average.

Just filled up my second tank, 20.3 mpg. 20.5 on first tank. This tank was 75% city 25% hwy. I have the auto, and most shifts were 3500 rpm for normal driving, 4500-6000(6k only once or twice) for fun. Had alot more fun on this tank :) . My first tank was 50/50 city/hwy. While I would like more mpg, I can live with 20. I have used 93 octane on both tanks (most stations here only have 87,89,and 93).
My last car (98 Volvo C70, chipped w/ turbo-back exh) got 29mpg on the hwy and 20-24 city, however my old LT1 camaro got 24 hwy and about 9-11 city :)

oh yeah...450 miles on the car.

I was on a little roadtrip Santa Cruz - Sacramento this weekend, ~ 300m roundtrip.

The car had just passed the 1000 mile mark, so no more babying. 300 miles on the freeway, at speeds 80 - 110 mph. The milage is actually better than when I 'babied' it.

My first tank had yielded 17.3 mpg, this time I got 20.4 mpg.
(That's 11.5 liters/ 100km)

The yellow fuel light came on at 265 m.

Oh, and the last two tanks I used 87 Octane gas.
In first and second gear, the car seems a little jerkier with the 87 gas though (???)

I've had my AT Winning Blue (GT package) RX8 since Aug 23. With 50/50 city/hiway I've been getting about 21+mpg.

I now have about 1500 miles on it. I took a 303 miles drive which took 12.5 gallons to fill. That works out to 24+ mpg. It was 95% hiway driving with speeds mostly between 50 and 60mph with the tach at 2500rpm and the AC on. Most of the trip was on Canadian roads (a bit smoother than some in Washington).

Since the AT is "window stickered" at 18 to 25mpg, my RX8 seems to be right in there.

Needless to say, I'm jazzed with my RX8. It's a head-turner where ever I go.

Originally posted by mngpao

[..]
That works out to 24+ mpg.
[..]
between 50 and 60mph with the tach at 2500rpm
[..]



I don't know how you were able to do that but thanks for verifying. I had my cruise control set to 72 (just under 3750 rpm in the MT) and intended to keep it that way for the rest of the trip to optimize the fuel consumption.

I lasted less than 10 minutes, then I got bored.

But thanks to you now we know that the numbers posted by EPA (!) are for real. This is no sarcasm.

-Peter

ptiemann:

I usually take it easy with new cars and since I received a speeding ticket I've stayed within the speed limit. If I keep my record clean thru December, I get the ticket dismissed.

Originally posted by mngpao
ptiemann:

I usually take it easy with new cars and since I received a speeding ticket I've stayed within the speed limit. If I keep my record clean thru December, I get the ticket dismissed.

I hear you, I got two tickets in the past 10 months, so I need to be careful. No speeding tickets for me though.

I didn't mean to make fun at you. Sorry if it came over like that.

-Peter