E15 is gasoline that contains up 15 percent ethanol and is fairly controversial. Right now, most service stations use gasoline blended with up 10 percent ethanol. And beyond the feeling many drivers have that the fuel hurts fuel economy, automakers contend that E15 “can degrade rubber, plastic, metal and other materials in vehicles not designed to handle it,” according to the Detroit News.
The EPA approved the fuel for use in vehicles from 2001 and later and did not approve it for use in motorcycles, off-road equipment and engines or heavy-duty gas engines. As Popular Mechanics notes, the Alliance of Automobile Manufacturers led a group of other organizations in challenging a lower court’s ruling that the EPA’s approval of E15 was OK.
Saying that the AAM and other group’s lacked legal standing, the Supreme Court passed on hearing the case.
“It is not in the long-term interest of the government, automakers, fuel providers or the ethanol industry itself to find out down the road that vehicle problems are occurring from rushing E15 into the national marketplace,” Alliance of Automobile Manufacturers spokesman Wade Newton told the Detroit News. “EPA approved E15 for cars retroactively, even though those vehicles were never designed to run on this more corrosive fuel.”
Beyond the uncertainty of how much damage E15 is capable of, there is also the simple worry that consumers will fill make the mistake of filling their lawnmowers, chainsaws and other home equipment with the fuel which can severely damage small engines.