The energy deficit ethanol suffers compared to gasoline is is about 75%. That is, one unit of ethanol hold approxomately 75% of the energy of the same unit of gasoline. I could find you a link if you really want one...
But ethanol has a higher octane rating (near 103-105), and in the future when/if engines are designed to maximize ethanol burning and not gasoline, this could possibly be expolited to more efficiently extract that energy; narrowing the mileage gap it suffers compared to gas.
$4.00+ gas is pretty solid
, and Coskata and other cellulosic ethanol companies expect to be able to produce ethanol for as little as $1.00 a gallon. I doubled it to eliminate any arguments about cost of production v. resale and taxes, etc...but you get the jist of it.
They ARE testing different blends, and it turns out that certain "mid-range" blends like E35, yields consistant mileage improvements compared to pure gasoline, which is exciting!
(can't find the darn link--I
know it's on the site somewhere....)