Also make sure your MAF is clean. It probably doesn't help but they do build up a little bit of dust. Also, on e85, I run OEM plugs. You can also add a liberal amount of off boost timing.

 

On the last few tanks of e85 i have averaged between 12-14mpg mix of city and highway. But one tank i was driving the car hard and in boost often i averaged less than 10mpg. But at $1.95 a gallon and the huge hp gain i'm not complaining lol. Gotta love this stuff car runs great.

 

I have been running e85 long enough to average many tanks together to get an overall of 16mpg. To break even, cost wise, with pump 91 and the drop in mpg with e, the pump has to cost over $2.55 a gallon. Performance wise, no contest!

 

Just switched over on Monday night... still not anywhere near 100% tuned (haven't really touched the timing, mostly just made changes for the 1000cc injectors/fuel pump and leaning it out a bit, start up timing).

In two days driving I'm seeing within 1-2 mpg of what I was getting on 93 when I just drive like a sane adult (in fact, got mid 23's today on the way to work according to the HUD). If I wail on it, I can hear each gallon of fuel trying to pass each other on the way into the combustion chamber (3-4mpg less than what I would get with 93). I'm ok with that

We'll see what bumping timing up does though once I burn through this tank (I put 13.6g of E85 into the 14.5g X tank, so there's a little 93 left in there).

 

I'd wait till you have pure E85 in the tank to do any mileage estimates. The gallon or so of pump will skew it.

- Bryan

 

14.6mpg/220 a tank....Thats with an autox weekend. I've gotten as high as 260 or a little more. But that's no fun

 

If I got 14mpg I wouldn't be able to make it from one E85 station to the next LOL. Heck my buddys 1g GSX that I tuned up for him gets deep into the 20mpg territory on summer E85 when he drives it from central PA to long island and that engine is a 20 year old brick.

 

How are you getting 14.6 mpg when you are going 220 miles per tank? The total capacity of the fuel tank is 14 gallons, so if you ran the tank completely dry, I calculate 220/14 = 15.7 mpg. The reserve light goes on at about 12 gallons, so if you filled it up at that time, it would be 18.3 mpg.

 

That's with autoxing on the weekend. Normal daily is high 200's.

And as far as the 14 gallon tank, I found out it was 15 because I just about ran out of E on the way back from a race (to the point my car was almost dieing, especially when taking any turn). When I got to the station I filled up 14.7 gallons. Got the receipt to prove it.

It's funny you should mention that, because on Monday (after racing on Sat and Sun) I went to work and told a friend (who owns an Evo) exactly what you said (and what I thought also (14 gallon tank)) and showed him the receipt.

I also run full time closed loop....no full time open loop with leaned out cells. I get better drive ability with the car set like that, although the mpg's do suffer, but not enough to make me switch back to full open

 

Full time closed loop? Not full time open loop?...

 

yup. Except for the first few minutes or whatever.

 

The 0.7 gallons is the fuel line and other associated plumbing. The actual tank is as the manufacturer states. Either that or your gas station is ripping you off.

 

Weird. I was thinking of messing around with full time open loop...

 

So just to follow up on this.... I'm not 100% tuned, but close enough. I'm averaging between 12 and 15mpg. Typically a mix of highway, street and autocross. I went 179 miles today and I have 1/8th a tank left right now.

The HUD is definitely off though. It says anywhere between 24 and 16mpg but I can watch the fuel gauge go down lol.

 

well , i averaged 1 tank a week. i average about 15 mile a day. sometimes under boost. you do the math. Iam on fp red turbo, 1200cc injector. 2 walbro fuelpump, 272 cams full boltons. 30psi boost. at 4000rpm. 460whp,450wtrg.