The Environmental Protection Agency (EPA) contends that its proposal to sharply reduce the 2014 requirement for ethanol use in the Renewable Fuels Standard (RFS) was driv­­en by the lack of infrastructure in the nation’s fuel supply system. The ag­­ency said the reductions were inevitable because it is too difficult to go beyond a 10 percent blend of ethanol in the U.S. gasoline total, the so-called blend wall.

But the agency’s reasoning doesn’t consider increased use of E85, according to a new paper written by Bruce Babcock and Sebastien Pouliot at Iowa State University’s Center for Ag­­ricultural Research and Dev­elopment (CARD).

By pushing to increase consumption of E85, a fuel that contains up to 85 percent ethanol, through increased outlets and more rational...