Your point about the renewability of biofuels is a very good one, gpsman1.

I would be interested to know the difference in energy density between the ethanol you're talking about, the 3/5 Dust-to-dust ratio you mention, and the gas used to make it. Because if we really want apples-to-apples, we need to talk about not just a gallon of ethanol for every gallon of gas, but a mile travelled on an ethanol gallon v. a mile travelled on a gas gallon. So there's another ratio here, and if it's low enough, then what you're saying is still reasonable, though less favorable than you describe, but if it's high, then it's a bad idea. By low and high I mean the following:

If you can get 175% the energy out of a gallon of gas as the energy you get from a gallon of ethanol, and can go 175% the distance on it, then 3/5 * 7/4 = 21/20ths of the energy used to produce it compared to what you get out of it. Bad deal.

If the number is 125%, then 3/5 * 5/4 = 3/4 of the energy gained was used to produce it, so you have a reasonable argument.

I'm not sure what the actual number is, but I'm certain that ethanol isn't as energy dense as gas, so it's over 100%. The important dividing line is whether it's over 166% or not. Is it? Close?