U.S. drivers will be putting less ethanol in their tanks.

The Environmental Protection Agency proposed Friday to cut the amount of ethanol required in gasoline from what was originally required under the 2007 Energy Independence and Security Act, The Detroit News reports.

The EPA wants to reduce the amount of ethanol and other biofuels the law requires to be blended with gasoline to 15.21 billion gallons. That's about 20 percent less than the original 2014 target of 18.15 billion gallons.

Why the change of plans?

The law requires biofuels to be blended with gasoline in increasing amounts, but those amounts as determined by volume--not as a percentage of the fuel being used.

When Congress passed the law in 2007, it was assumed that U.S. gasoline consumption would continue to rise. In fact, different studies have shown that U.S. gasoline usage peaked in 2006, and that U.S. drivers also have fewer cars, and are driving them less.

More harm than good?

The AAA praised the EPA decision, saying the original targets were unrealistic and had the potential of "putting motorists and their vehicles at risk."

Last year, the AAA came out against E15--a blend of 15 percent ethanol and 85 percent gasoline--claiming that only five percent of light-duty vehicles on U.S. roads could use the fuel. The EPA says E15 can be used in cars built in 2001 or later.

The controversy centers on potential damage E15 can do to engines. Despite several automakers approving it for use in recent models, many believe EPA approval was rushed.

E15 has five percent more ethanol than 50 percent more ethanol than the E10 blend currently sold at nearly all of the nation's 180,000 gas pumps. Ethanol has less energy density than gasoline--meaning slightly worse fuel economy--but that's mitigated by a lower cost, roughly 10 to 15 cents per gallon less than E10.

Brazilian sugarcane

Brazilian sugarcane

Growers disapprove

 However, there's one group that probably won't approve of the EPA's decision: growers.

"Slashing the 2014 target for advanced biofuels would be a huge step backwards," Leticia Phillips, North American Representative for UNICA, the Brazilian Sugarcane Industry Association, said in a statement.

Brazil has tried to promote sugarcane ethanol as an alternative to corn-based ethanol for U.S. biofuel needs.

36 billion gallons by 2022

Despite criticism from the auto industry--and concerns over ethanol's impact on food production, land use, and water consumption--the EPA has held fast to a goal of using 36 billion gallons of renewable fuels by 2022.

Since the Energy Independence and Security Act was passed in 2007, that goal has seemed like an inevitably. Could that no longer be the case?

Updated: A previous version of this article stated that E15 contained five percent more ethanol than E10. While five percent more of the overall blend of E15 is ethanol, it actually contains 50 percent more ethanol than E10. Thanks to reader John C. Briggs for pointing that out.


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