What Octane gas to use?!!!

[TheOtherNick]

But apparently it also slows your car down too. Did you look at the run times?

Yeah in a flex fuel vehicle designed for economy. Not a blown car with someone tuning it. Fosho runs e-85 and gained a **** ton of timing. E-85 is 103 octane. Higher octane = less heat = more timing/boost= more power.

[SeanGTP]

Yeah in a flex fuel vehicle designed for economy. Not a blown car with someone tuning it. Fosho runs e-85 and gained a **** ton of timing. E-85 is 103 octane. Higher octane = less heat = more timing/boost= more power.

Didn't catch that part. My bad.

[ZR1Vette09]

Yeah in a flex fuel vehicle designed for economy. Not a blown car with someone tuning it.

isn't the point of that article that even though its a flex fuel it doesn't get better economy? forgive my ignorance, i know nothing about tuning.

[FoSHO99]

E-85 initially takes 30-40% more fuel, but after tuning for it you can gain back some mpg and still are only paying $2 a gallon for 104 octane. There are plenty of high powered forced induction street cars that swear by it and have dyno results to prove the gains. One person hit 430whp on a small turbo kit and stock engine and cam, 1.9 rockers running E85. I can say it kills at least 6-10* of knock.

If I wanted cheap fuel economy I would put 87 octane in and tune for that to run safe, granted I would have to pull about 10 degrees of timing and more, but that would not be fun at all.