Gasoline may soon contain more ethanol after an Environmental Protection Agency decision Wednesday. The EPA is now allowing up to 15 percent ethanol in gas, but only for cars made after 2007.

It could take months before higher concentrations of ethanol start showing up at stations — and once it does, it will be labeled so drivers with older cars don’t use it.

The Heated Battle Over What’s In Fuel

Today, gasoline contains up to 10 percent ethanol. The ethanol industry — including corn farmers — has wanted to increase that to 15 percent. That would be a big financial boost for them.

But oil companies, which stand to lose market share, have raised concerns about adding more ethanol to the nation’s fuel supply.

In 2007, Congress set a goal of using 36 billion gallons of renewable fuels, like ethanol, by 2022. To reach such an aggressive goal, the ethanol industry in 2009 asked the Environmental Protection Agency to raise the current 10 percent limit on ethanol in gasoline to 15 percent.

But there are concerns that increasing the amount of ethanol in gasoline could damage cars already on the road. Ethanol burns hotter than gasoline and that could damage engine parts. The ethanol industry submitted reams of studies to support their claim that boosting ethanol is safe.

“In our opinion, the data they submitted is inadequate,” says Patrick Kelly, policy adviser with the American Petroleum Institute. “They’ve taken a lot of good information and then made conclusions that were based on the judgment of the authors rather than based upon the data that was actually provided in the studies.”

The U.S. burned 138 billion gallons of gas last year, so losing just 5 percent of that market to another form of fuel, like ethanol, means the oil industry could lose billions of dollars. So the oil industry’s concerns raised a few eyebrows.

“There’s some very well-financed, vested interests that do not want to see our industry succeed,” says Tom Buis, CEO of Growth Energy, an ethanol trade group.

Still, the EPA said it wanted to rely on independent data to make such an important decision. So the agency said it would rely on Department of Energy studies.

“We are not afraid of the testing that’s being done, because we think the tests will confirm what we submitted in March of 2009,” Buis says.

The DOE is testing 82 vehicles in its labs. Some of the cars are being driven up to 120,000 miles to see if burning gas with 15 percent ethanol will damage them. The agency has spent more than $40 million on testing so far. In some cases, researchers had to buy three identical versions of the same car.

“We’ll run one of them on zero percent ethanol, one of them on 10 percent ethanol and one of them on 15 percent ethanol,” says Bob McCormick, principal engineer at DOE’s National Renewable Energy Lab in Golden, Colo.

The bulk of the testing is aimed at making sure more ethanol in gas doesn’t damage pollution control devices on cars. But in some cases, the engines will be removed from the cars and taken apart. That’s so the agency can “look for any degradation of parts or deposits or anything like that that could cause the type of problem that I think drivers are more concerned about,” McCormick says.

Only Certain Cars Will Take The Fuel

Wednesday’s announcement applies only to cars less than three years old. The DOE is continuing to test cars built between 2000 and 2006. Once those tests are done — probably in November — the EPA will announce whether gas with 15 percent ethanol is safe for them, too.

The EPA denied a request to use 15 percent ethanol in cars built before 2000. They were never built to burn higher concentrations of ethanol and the new fuel may damage parts of those engines.

“The earlier vehicles we have concerns from an engineering perspective about the design,” says Gina McCarthy, EPA assistant administrator for air and radiation. “We have questions about whether E15 will be compatible and that’s why we will need additional test results.”

Among those anxious to see the results are auto manufacturers. They worry that increasing ethanol might also increase their costs if they have to fix more cars under warranty. In some cases, manufacturers warn burning fuel with higher than 10 percent ethanol could void a warranty. Copyright 2010 National Public Radio. To see more, visit http://www.npr.org/.