I won't go into all of the details.
2300 miles since 04/15/04.
87 octane amoco/bp or shell gives me consistently 20.9 mpg.

 

hasg: I'm using 93 octane. You don't see 91 much in my neighborhood. The last three tanks have averaged 20.3 mpg.

 

I do mostly hwy and have never got under 23mpg and have 3 times got 27.5mpg. Around town I get 16.5-17.5 and thats having some fun too....

 

You guys/gals should be counting your blessings... 3,000 miles and I average 14.53 mpg wtih an auto...

And one dealership in So Cal says my car is "fine." WTF?

 

i started keeping receipts after my seventh tank and have just broken the 16mpg average after about 5k miles of roughly 50% highway. id bet that those first tanks would put be back in the 14s though...

 

The 8's mpg is improving as the engine is broken in.
Since delivery I'm getting 18.7 mpg
19.62 mpg since the M-flash about 2k miles travelled since the flash only 3k mi. total on the engine.
Got 21.2 mpg on a trip this weekend with the AC on and driving with the traffic on 95. 4-5k shift points.

I'm content with the improving mileage and very happy with the overall performance of the 8.

 

On an aside, do you notice a quick on off of the AC motor when it is on? Mine seems to run nearly constantly, and switches off only for brief stretches of 30 seconds or so. Is this normal?

 

I just finished my second tank after the M patch 19.99 mpg in mixed driving. Before the flash I got 16.5 to 16.9 now I get 19.2 to 19.99. I didn't get it for the mileage but I am very satisfied with the way it runs now and with the mileage. I bet I can get 26 mpg on a trip (i got 24.2 before).

 

serch for AC cycling. there are many reports of this. there is also a new part available which helps reduce/eliminate this cycling. however the part is on back order in the US until i think june/july.

 

Is it possible to make this thread a Sticky?

 

Bumped for an update.

 

Bumped for an update.

 

Man, you are golden.

After almost 3000 miles, my average with my auto was 14.5 mpg. I just got the M calibration and averaged 16 mpg. I'll have another fill today, take my average, and then install my K&N intake.

Don't know what will happend with the mpg but only time will tell...

 

I'm averaging about 15mpg, but I did hit 20mpg with highway driving. then again, the car has just over 800 miles

 

My first long road trip last week...Albuquerque NM to Colorado Springs CO. On the longest leg I got 26.7 mpg. Average speed was about 70 with A/C on. Average was 24.6 over the about 1000 miles driven. My usual in town is 17. I have about 7500 miles on the car..

 

Mine is like this too. I just entered my latest mpg data. During my latest long distance trip, I got 23 mpg. This was mostly I-20 and I-95 traffic running at around 75 - 80 mph. I usually set the cruise at 78 so the interstate driving was pretty consistent.

I didn't start tracking mpg until 2200 miles, and I have ~7200 on the odo now. My ongoing average has been 19.659 with a min of 17.399 which was during an autocross weekend, and max of 23.712 which was during this last trip with the A/C on all the time. Most of my driving has been relatively spirited city driving (except when the wife is in the car). All of my fillups have been with regular unleaded gas.

Overall, I'm pretty satisfied with the gas milage.

 

I now have 7400 miles on my 8... I am averaging 17.62 mpg with about 70% City and 30% highway. Trips that were 100% highway are almost always at 4000 rpms and 80mph on cruise. I end up with around 21.2 mpg on these trips. My worst milage was 14.75 mpg driving it VERY hard while showing it off to my fellow Marines. My best was 22.3 on a trip to Bristol for the Spring NASCAR race. It is of note that the Bristol trip occured right before 5000 miles. Prior to 5000, my gas mileage was 19.3mpg... Afterwards was 22.3 driving exactly the same way.

 

Bumped for an update!

 

No big surprise, around 400km for a tank of gas. That's about 250 miles (I think) / 14.9 gal. comes to 15-17 mpg.

Still doing the engine break-in thing and lots of stop and go traffic. Oh well, it can only improve from here.

 

Bumped for an update. My mileage does seem to be getting marginaly better since I started using 87 octane. Only time will tell.

 

Sorry for the delay but I suffered a bit of headspace due to my friend Paul Johnson's demise.

Well I will start posting all the info provided by that wonderful Palm OS program that someone posted a link to. That was the cats meow.

I also changed my oil a bit early due to a road trip I am taking next week from Newport News, VA to Medford, New York (Lawng Island) It was changed about 500 miles early.

I seem to be consuming less fuel but I think I have just curtailed my driving abit due to the price hikes. The car seems to be running just fine on the 87 oct. fuel so far I willl see how it fares on the long trip next week.

:p Cheers!

 

First three tank-fulls:

17.5 MPG-all city driving
18.5 MPG-almost all city driving
19.9 MPG-50/50 city and highway

Still breaking it in so mostly just cruising w/ shifts at 300/4000 rpm

 

I have had my RX8 about eight weeks and it has approx 4500 miles on it. I drive it mostly to work and back in Dallas traffic. I haven't been pleased with its fuel usage, but have accepted it. I try to drive very mildly, but have let the tiger loose a few times.

Over the weekend of June 25th - 27th I visited my parents in East Texas. I checked my mileage carefully and on the trip I got 23.96 miles per gallon. (89 octane). I was pleasantly surprised. I did have to resist running at high speed. I drove mostly between 62 and 64 mph. I have the automatic transmission.

It was rural driving. I had several stop signs, speed zones, and a couple of small towns, so it wasn't the same as interstate driving.

My conclusion is: The RX8 mileage problem is mostly caused by the way they are driven. They aren't stingy with fuel, but mine isn't any worse than my last car, an RX7.

 

Are mpg figures on stock cars? Would aero kits make a difference in mpg? Would a more aerodynamic car be able to get 5mpg more than a less aero car?
Tire pressure? Some on this forum run at pressures higher than the recomennded 32 psi. Less rolling resistance but sacrificing tires.
Lots of variables. Most fuel economy figures from manufacturers are obtained under ideal conditions not real world driving.
I'm getting about 17 mpg, mostly city, aggressive driving now. 2500kms on the odo. No body kits. I can't complain.
BTW, I was just reading the Lambo Gallardo gets 9mpg.

 

Mine is stock with no aerodynamic aides. All tires are kept at exactly 32psi.