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.

 

So she says... :D

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.

 

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.



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.

 

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.

 

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....

 

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:

 

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?

 

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.