I get about 10 mpg with my modded FD if I'm lucky https://www.nopistons.com/forums/pub...#>/biggrin.png



Looking for a new daily driver to replace my 4-door sedan. I commute about 70 miles total a day so I do have to be concious about mpg...what kind of of mpg are you RX-8 guys getting?



Thanks

if you get 10 MPG in your modded FD you must be doing something wrong. I get 17-19 city in my 94 and its ported with 350 rwhp.. If I push it really, really, really hard I could get 16 thats worst case.



my first fillup on the rx8 was 15. last time I got 17. this is city driving. BTW, you can use 87 octain in the rx8 and I tried that this time. I may get better gas mileage with that.

I've gotten an average of about 19MPG with a 250 mile a week commute with a mix of city/highway. Pure highway I can see as high as 26mpg, and heavy city as low as 15, but never below that.

I'm averaging a little over 15 mpg, almost entirely stop & go daily commuting, total miles so far about 1,600. It gets a few 10ths better with each fill-up.

I get about 18 MPG, mostly city/mountainess driving. It runs way to rich!

I seem to get 19mpg city/highway.. 21 on straight highway driving. I'm a bit dissappointed since I drive 60mi per day.. I do have a tendency to push it a bit when I get on open highways.



BTW - I ran across someone trying to put the 4 rotor into the rx-8 body but I forget the link to the site.. Anyone seen that and remember the link?

Funny I don't know other people's experiences, but the salesperson at Mazda the other day just tried to tell me it had been rerated that it was getting as high as 35 highway driving. It took all my will not to ask him what drugs he was on.

Anything for a sale. Salesmen are shameless.

Well it does not run rich when I logged the AFR's on the baileys wideband. 13.5.1 - 13.6.1 at WOT. It just has bad fuel economy.

Something is wrong with your wideband, that is too high for a stock 8. Should be around 12:1



Look here:



RX-8 A/F

Digisan, Most N/A cars run a leaner mixture than turboed cars. On a baileys wideband we see or tune tune 12.0.1 on turboed cars and on n/a cars we see or tune to 13.5.1. Also these are target values it can very from tuner to tuner.

Did you check the link I posted for you? 13.5 is not what the RX-8 runs stock, if that was the case it would be putting down over 200rwhp, and it's not. I agree with your statement, but it just doesn't apply to the the RX-8. The fuel mixture is very rich so the cat can last 120K mi.

Sorry but **** your link. I sent you a p.m. I dont gossip just the truth. Anyhow please post my link if you want.

Don't get mad at me because you can't use a wideband. You are the ONLY ONE that has measured the RX-8 at 13.5 A/F stock.



heffner PM quote:



"Digisan, you read too much on this forum. I logged the AFR's myself I know what it runs. Not to be a DICK but that is what I logged with a real AFR meter unlike most people on the homo nets. But live in your world of unrealistic dreams and dillusions of grandure. If it was to save the cat it would run lean! A rich cat will fail very quicly. Do research before you blab internet bable from theses guys. From the source!"



It is widely known why Mazda re-flashed the ECUs, simply to bring down the exhuast temps by richening the mixture so the cat will last 120,000 miles. Just because a car is running rich (I'm breaking new ground with this statement; typically cars run rich) doesn't mean the cat will fail prematurely, cat operating temps need to be kept in check. Of course, dumping fuel into the cat will cause it fail prematurely.





"This in part plays into the “lost power” issue with the RX-8. Mazda’s engineers have programmed the car to run “rich” at higher RPM’s in order to keep the exhaust gas temperatures down. Running a leaner mixture at these higher RPM’s may overheat and prematurely damage the cat, risking that dreaded word to every car maker….. recall!



We are certainly working on the exhaust, but the man-in-charge is currently in Japan and I must wait a couple more days for an update. My guess is that we are still several weeks away, sorry.



Jim Langer

Racing Beat"





heffner PM quote: "Do research before you blab internet bable from theses guys."



I suppose Jim at Racing Beat is internet bable as well? I smell a troll. https://www.nopistons.com/forums/pub...IR#>/boink.gif

Gotta go with the Digisan on that one, "pig rich" above 7500 rpm.



A simple fuel controller with a well designed 3D map will lean it out, and free up another 20+ hp. https://www.nopistons.com/forums/pub...DIR#>/ohmy.png



I personally drove around with a passenger seat full of broadband, EGT, and laptop, to develop the maps. My buddy 'Canzoomer' can hook you up.....

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doc

If FEs are like FDs then they will run richer for the first 20,000 miles to ensure a safer break in. I could not find the link but it is in the FD factory service manual. Something changes once the car flips over 20K miles then the car runs less rich https://www.nopistons.com/forums/pub...#>/biggrin.png it sounds like bullshit but for real find an FD FSM or ask a 3rd gen guru about it. But, anyway we should see an improvement in the 8's fuel economy after 20K miles...

Unfortunately, the fuel maps were changed to comply with the new emissions standards, not for engine break-in. :(

I was getting 13mpg. That was brand new, not broken in, idling alot in the cold. I would let it idle for a while, I didn't want to get in a cold cold car. Anyway, 1400 miles on her now, getting like 18mpg. All city. Not bad.