ORNL fuels, engines and emissions scientists utilized the diagnostic and testing capabilities of DOE’s National Transportation Research Center and proved that gasoline containing 15% ethanol (E15) would not cause emission control system failure in light-duty vehicles. The study provided critical data used by the U.S. Environmental Protection Agency, or EPA, to underpin the landmark 2011 national fuel policy decision to allow 15% ethanol/gasoline blends in vehicle model year 2001 and newer light-duty cars and trucks. The EPA decision increased the allowable ethanol blend from 10% to 15%, breaking the ‘blend wall’ that had prevented compliance with the provisions of the Energy Independence and Security Act of 2007.
Over the course of 24 months, researchers drove 86 light-duty vehicles up to 120,000 miles to age their emissions control systems while fueling them with gasoline blends containing up to 20% ethanol. The researchers conducted approximately 1,000 emissions tests on the 86 vehicles to evaluate the impacts of the ethanol blends on tailpipe emissions. The vehicles were driven an aggregate distance of more than six million miles, which was equivalent to more than 12 round trips to the moon.