The U.S. has nearly 100 ethanol plants, with dozens more under construction. Supporters say the corn-based fuel is cleaner and more cost effective. But how does ethanol perform when compared to pure gasoline? WMTV NBC 15 News (Madison, Wis.) enlisted the help of a University of Wisconsin expert Glenn Bower to put E10 on trial. Bower’s process for testing the fuel economy of E10 versus pure gasoline involves determining each fuel’s volume by weight, taking a test drive with each fuel in his Ford F-250 truck and monitoring engine performance, then comparing remaining fuel volume after the drive to determine how much fuel was used per mile. Going into the trial, Bower predicted that the E10 blend would have a three to five percent decrease in fuel economy compared to pure gasoline. However, Bower's F-250 got 13.74 miles per gallon on E10 versus 11.5 miles per gallon on pure gasoline, NBC 15 News reports."I was a little surprised at the results. I didn't think the ethanol would be that much better than straight gasoline," he says.A study of fuel economy by the American Coalition for Ethanol last year offers mixed results. It says three different vehicles averaged 1.5 percent lower mileage with E10 compared to unleaded gas. Bower says the type of vehicle used to test the fuels as well as variations in the base fuel could impact the results. He used a winter blend of E10.Whatever the fuel economy, proponents of ethanol claim it saves customers money because it's generally lower priced. Generally, all vehicles can run on E10, but E85 requires a flexible fuel vehicle.