WASHINGTON—The Environmental Protection Agency is poised to approve higher levels of corn-based ethanol in gasoline for all cars manufactured in the past decade.
Two people familiar with the decision said late Thursday the agency is expected to announce on Friday that 15 percent ethanol in gasoline is safe for cars manufactured between 2001 and 2006. Both officials requested anonymity because they were not authorized to speak publicly about the decision.
In October, the agency approved 15 percent ethanol for all cars and light-duty trucks manufactured since 2007. The maximum gasoline blend has been 10 percent ethanol.
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 non-road engines -- because there is not sufficient testing to support such an approval.
Ethanol is popular in farm country because most of it comes from corn and other grains. It faces strong opposition, however, from the auto industry, environmentalists, cattle ranchers, food companies and a broad coalition of other groups.
Opponents argue that the increase in production of corn and its diversion into ethanol is making animal feed more expensive, raising prices at the grocery store and tearing up the land. Manufacturers of smaller engines, such as those found in lawn mowers and boats, also oppose increasing the use of the fuel, saying those engines are not designed for the higher concentrations.
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 has required refiners to blend 36 billion gallons of biofuels, mostly ethanol, into auto fuel by 2022.
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.
The EPA has delayed decisions on using 15 percent ethanol several times as the agency and the Energy Department have tested the ethanol-blended gasoline to make sure it is safe. The agency has only approved the blend for newer cars and trucks because they have more durable emissions systems.
Ethanol burns hotter than gasoline, causing catalytic converters, which help clean engine emissions, to break down faster.