Few people seem to know this, but owing to the congressional mandate, since 2008, the gasoline you purchase contains 10 percent ethanol. Because ethanol has a lower energy density than petroleum, a 90/10 fuel blend reduces miles per gallon by about 3 percent. So if your mileage has seemed a little low lately, that's because it is a little low -- Congress effectively mandated that gasoline become less efficient.This is outrageous, especially when you consider the well-known (outside Washington) hypothesis that ethanol takes more energy input to produce than it, in fact, outputs.
I'd noticed the "10% Biofuel" stickers on the gas pumps, and I knew about the massive debt-funded subsidies going to rich corporate farmers in Iowa, but I didn't know it was lowering my fuel efficiency.
Memo to Iowa: I'll take my corn on the cob, please, not in the tank. Next time you see an Iowan, ask him for your money back.