The Alliance of Automobile Manufacturers and other organizations challenged a lower court’s decision to uphold the EPA’s approval of E15.
The Supreme Court passed on hearing the case, saying that the challenge lacked legal standing.
Most service stations currently use gasoline containing up to 10 percent ethanol.
The increase to 15 percent ethanol is controversial because automakers have said E15 can degrade certain materials like rubber, plastic and metal in vehicles. Some consumers have also expressed concern over the possibility of mistakenly using the fuel in home equipment such as lawnmowers and chainsaws, which have small engines that the fuel could severely damage.
The EPA approved E15 for use in vehicles made in 2001 or later. The fuel was not approved for use in motorcycles, off-road equipment and engines or heavy-duty gas engines.
