Most motor fuel today is "enhanced" with ethanol, to a maximum amount of 10% ...legally. Its purpose is to oxygenate the fuel so it burns leaner and cleaner, especially in winter. It does work, it is effective, but mileage suffers a bit. Also cold weather causes a decline in mileage as well.
Not sure of E15 , havent heard of it.
E 85 is 85 % ethanol, the 15% of gasoline (petrol base)is to aid in cold start of the motor.
Ethanol is pretty destructive to fuel system parts.
It can be used to run a high compressio engine though, like 12 -14 to 1 compression, as it is alcohol and it works better with high compression.
Sux...its a matter of intended use.
I wouldnt buy a vehicle that runs on "flex fuel" or E 85 , but i would build a street machine with High CR and run E 85 in a minute. Trouble is , it isnt readily available every where.
Using the correct fuel system components with correct metalurgy is absolutely necessary to keep the fuel system from literally disolving.
Fact is stranger than Fiction
Last edited by LATECH; 01-25-2013 at 02:54 PM.