Consumer Reports (CR) stated in a recent study that E-85 is more expensive than gasoline but less polluting. In the comment below, American Enterprise Institute scholar Joel Schwartz argues that the pollution reduction from using E-85 rather than gasoline is speculative and, in any case, too small to matter.

CR is right about the high effective cost of E85 (though they fail to mention the subsidies that make the real cost even higher), but their claim that ethanol is cleaner is misleading at best and possibly wrong.

CR claims E85 vehicles put out less air pollution. But that’s based on testing one car once on each fuel. I doubt anyone really knows whether E85 vehicles will put out less pollution than comparable gasoline vehicles under in-use conditions. Any differences would probably have no practical significance. New gasoline autos are near-zero-emission vehicles. Any percentage difference between gasoline and E85 would be a tiny absolute difference.

CR’s article is profoundly misleading on air pollution from gasoline vs. E85. The article says:

“Ethanol, however, emits acetaldehyde, a probable carcinogen and something that standard emissions-testing equipment is not designed to measure. But that might be a relatively minor evil. ‘Acetaldehyde is bad,’ says James Cannon, president of Energy Futures, an alternative-transportation publication, ‘but not nearly as bad as some of the emissions from gasoline.’”

This creates the false impression that whether you use gasoline or E85 has a material effect on your car’s pollutant emissions and that E85 is a big improvement. But all cars have to meet the near-zero Tier 2 standards regardless of what fuel they run on. That includes an emissions standard of 0.075 grams/mile for organic compounds (up to 50,000 miles; 0.09 between 50k and 120k miles), compared with somewhere around 0.75 grams/mile for the average car on the road today.