Read today’s editorial on ethanol in the Wall Street Journal. Here’s the heart of it:

the EPA lifted the cap on how much ethanol is allowed to be mixed into gasoline to meet the annual consumption mandates in the 2007 energy bill, which will rise to 36 billion gallons by 2022. Until last week, this per-gallon “blend wall” stood at 10%, because ethanol is highly corrosive and can damage engines and exhaust systems and impair other features. The practical problem with this industrial planning is that Americans don’t use enough gas to meet the mandates.