[WardL]

When I said ethanol has 115 octane, I meant a blend of 95% ethanol and 5% denaturant has about an 115 octane. E85 is defined as fuel with between 50% and 85% ethanol! The ethanol will give you the HP, but the energy content is lower so you get less gas mileage. 1/3 less gas mileage is typical with E85, but you still get more HP. You should not run E85 unless you have a flex-fuel vehicle. E85 requires steel fuel lines and special components to operate safely.