Ethanol has a lower heat of combution value than gasoline. However, it
does make water miscible with gasoline so it will help keep your fuel
line from freezing in the winter. Otherwise its not of any advantage
to use with gasoline. Why not use ten percent isopropyl alcohol. It
has a higher heat of combustion than gasoline and is extremely
inexpensive. Probably would attack the plastic and rubber components
in many fuel systems though.
