Corn based ethanol is just stupid. Because we depend on petroleum-based fertilizers, it takes two calories of petroleum to grow one calorie of corn*. This is before any calorie loss from converting those sugars to alcohol.
The idea that corn-based fuels reduce our dependency on petroleum is FALSE. At this point, it's just a way to prop up the corn farmers a little bit more. What a boondoggle.
*Reference on petroleum calories for corn calories: The Omnivore's Dilemma by Michael Pollun