SASless is right - in fact it takes 3/4 gallon of gas to make 1 gallon of alcohol - for those who think this is sound energy policy, I have a car that runs on water.
And the laughable idea that we will run out of oil is simply not true - as long as we are willing to spend $60 per barrel or more!
What is the real problem is not energy as it is - but how we stop global warming if we continue to burn carbon. Cutbacks on energy use, massive resurgence of nuclear power and wind/tide/solar are all coming. Aviation will use oil products for a long time, due to its density and portability, but liquid hydrogen is an alternative that can work, as well.