ReserveBum - I agree with your assessment about ethanol-free gas providing better fuel economy. Ethanol has a lower BTU/lb energy content than gasoline. Running fuel without it translates to having more power-dense fuel. On vehicles that can use E85, it takes significantly more fuel to make the same power levels as on E10 gas. The turbo tuning crowd really likes E85 since the ethanol burns is more resistant to detonation and therefore you can run higher boost...but you have to run larger injectors to get enough into the engine.
I agree that running higher than specified octane is a waste UNLESS the engine has been pulling timing due to diagnosed misfires, in which case the absence of those will return the fuel/timing to normal and generate more power as a result.
Here in central Flogida I can get ethanol free 91 at multiple stations. I use it some and it makes a slight mpg difference but not much. Doesn't matter what I use I very seldom break the 40's. I am normally 36-38 mpg!
Reply With Quote
