E85 MPG
 

I know some are curious of what kind of mpg they'll get if they change over to E85 full time. I'll start with the two tanks I've run through to this point, and hopefully others can add info for other conditions / driving styles to round it out.

First tank 18 MPG
Second Tank 17.5 MPG

Thats 70-72% of my average pumpgas MPG

For reference I was getting 25 MPG on 93 pumpgas with the Visconti tune, and slightly lower than that on the stock flash. I know that a lot of people will see higher numbers, but will have had higher numbers than I did on pumpgas. I do not see much in the way of open highway miles and am pretty liberal with the throttle.

Also, these are hard numbers from odo / receipts. The dash gauge is off far worse with E85 than pumpgas

For reference, here is the E85 tune info http://www.ft86club.com/forums/showthread.php?t=15753

Did you need to modify the engine at all to accommodate E85 (ie. injectors, fuel lines, etc.)?

Obviously, I haven't used E85 in my FR-S yet, but if it is cheaper to run per mile in comparison to 93 octane, I'll probably switch over.

All stock aside from tune. Fuel will cost you more, but performance increase is dramatic.

Just curious, did you figure out how much more money your actually spending with this current milage? I hear E85 is cheaper to buy, so, wondering how it all averages out. I think this will also be important to others who have not yet purchased.

Here are my averages:

Stock Tune: 28-29 MPG (mixed city/hwy)
93 Visconti Tune: 31-33 MPG (mixed)
e85 Tune: 25-26 MPG (mixed, but beat it quite a bit)

Cool, cool.

25-26 sounds good to me lol...to you and DSTL, is there a big difference between the 93 tune and e85 tune? Or is it just an extra kick?

I honestly don't want to do the math since I know it's more $, ha. If I'm not mistaken assuming you would get 70% of the mpg on E85 as pumpgas you would take 1/.7 = 1.43, multiply 1.43 by your local E85 price and compare that to what you're paying for pumpagas. In that case, for me the equivalent for fuel cost apples to apples, it would be the same if 93 octane was $4.85 (E85 is 3.39 here). Obviously cost is higher, but also get some serious performance gains. Worth it to me. Hope that math is right but sure you get the gist.

Edit: 2012 EPA Flex Fuel data for comparison. Pretty inline with results here http://www.fueleconomy.gov/feg/byfuel/FFV2012.shtml

Just got home and did the quick math on this. In my case at least, with 93 at $4.09 and E85 at $3.39, the annual cost difference at 15,000 miles is $450 more to run E85. I'll gladly pay that for 35HP over stock (20ish over pumpgas tune)