[from occupied ga]

Pure ethanol will run in an engine with a compression ration of 19.5:1 If you tried 87 octane gasoline in the same engine, it would barely run, if ...

So what? None of this is relevant. If you'd ever heard of the first law of thermodynamics you'd know know too. It takes energy to accelerate mass and overcome friction. Engines are limited in their efficiency by the theoretical limit of their cycle. Changing the compression ration helps a little bit, but the basic limitations are available energy in the fuel and mass of the vehicle. Ie going from 10 or 11 to 1 to 19 to one doesn't make a lot of difference because of the law of diminishing returns. Here

is how compression affects efficiency for an otto cycle. You can read the whole thing at http://ocw.mit.edu/ans7870/16/16.unified/thermoF03/chapter_5.htm Increase mass = worse MPG, decrease fuel energy = worse MPG. Increase compression over the 10 - 11 range in most modern vehicles = SLIGHTLY increased MPG

[Mr. Lucky]

That's all fine, but at 19.5:1 compression ration, the engine will operate more efficiently on ethanol than 87 octane gasoline.

[Mr. Lucky]

I should have mentioned that you can Google on something to the effect of "High efficiency Engine Technologies for Alcohol Fuel" to review the EPA's actual results from increasing compression ratios.