WASHINGTON — Nearly two-thirds of cars on the road could have more corn-based ethanol in their fuel tanks under an Environmental Protection Agency decision Friday.
The agency said that 15 percent ethanol blended with gasoline is safe for cars and light-duty trucks manufactured between 2001 and 2006, expanding an October decision that the higher blend is safe for cars built since 2007. The maximum gasoline blend has been 10 percent ethanol.
The fuel is popular in farm country because most ethanol comes from corn and other grains. It faces strong opposition, however, from the auto industry, environmentalists, cattle ranchers, food companies and others. Those groups say that using corn to make ethanol makes animal feed more expensive, raises prices at the grocery store and tears up the land. There have already been several lawsuits filed against the EPA — including one filed by automakers, boat manufacturers and outdoor power equipment manufacturers — since the agency decided to allow the higher blends for newer cars in October.
Ethanol burns hotter than gasoline, causing catalytic converters, which help clean engine emissions, to break down faster.
Automakers continued to criticize the EPA on the decision Friday.
"Any new fuel's success depends on how it's accepted by consumers, and automakers still have concerns on behalf of our customers," said a statement from the Alliance of Automobile Manufacturers, which represents General Motors, Toyota, Ford, Chrysler and other automakers. "We believe more research is needed to determine how increased ethanol levels could affect vehicles that were designed and warranted for (10 percent ethanol)."
Critics said the change could be frustrating for drivers of older cars who will have to figure out which service station pump to use. And they argue that many retailers will opt not to sell the higher blend because of the expense of adding new pumps and signs.
"It seems like corn growers and the ethanol industry are the only real winners here," said Craig Cox of the Environmental Working Group, an advocacy group that opposes use of the fuel.
The Obama administration has remained supportive of the renewable fuel, and the EPA has said a congressional mandate for increased ethanol use can't be achieved without allowing higher-percentage blends. Congress, driven by a broad coalition of members from farm states, has required refiners to blend 36 billion gallons of biofuels, mostly ethanol, into auto fuel by 2022.
Agriculture Secretary Tom Vilsack said after the decision that expanding the use of ethanol in gasoline "gives consumers the option of purchasing domestically produced renewable transportation fuels" and supporting American farmers and ranchers.
The EPA has said there won't be a decision any time soon on boosting the ethanol concentration for cars and light trucks manufactured before 2001 — or for motorcycles, heavy-duty vehicles or nonroad engines — because there is not sufficient testing to support such an approval.