the problem with ethanol is that while it has a higher octane rating, the amount of boom in the same volumes of gas and ethanol is a big difference.
octane ratings are simply under what presure the fuel explodes, but it says nothing about BTU's. the BTU of gas vs. ethanol is a pretty big difference.
and moral of the story-
gas > ethanol
Energy density - Wikipedia, the free encyclopedia
/\ pretty cool article explaining energy density.
Gasoline- 34.6 MJ/L
Ethanol- 24 MJ/L