From the research I've done on this subject. First, the taxpayers are subsidizing the production of ethanol, the senators from the area did a great job. Secondly, Ethanol production is not environmentally friendly as one might think. Third, this artificial demand has driven up the price of corn that has caused the prices of many foods to go up, which ironically cause to double the animosity in the rest of the world that rely on US exports of grain, add that to the loss of revenue to many countries due to oil prices falling...not good. Lastly, you get at least 10% less mileage so you have to buy more which offsets any gains.
my .02. Any time the government is helping you, you lose 2X the gain, unless you are not a citizen, of course. Maybe we could save gas by have illegals pull our trucks and save diesel?