mmjames

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??

MVCalypso

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

MVCalypso

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

Dave

TJRX8

I'm trying, but in this car...dang is it tough!

canzoomer

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.

TJRX8

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.

khoney

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.

seahaven

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.

khoney

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.

TybeeRX-8

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

TJRX8

Amen brother! I couldn't have said it better myself, except substitute "Central Fl." for "No. CA".

Rotor_Newbie

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

mikeb

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

TJRX8

Wow. 214 miles/12.3 Gals= 17.4 mpg.

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

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

tminus3

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! :-)

TT2RX8

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

Bye bye 8!

TJRX8

15.5 on the last tank.

mikeb

your gas should improve around 2k

ectomort

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.

mmjames

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.

8_wannabe

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.

shebam

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.

8_wannabe

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.

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.
Not much change:
in 198km, got 16.7l/km / 14.12MPG.

Hoping it might change soon!!

Rotor_Newbie

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