Gasoline containing 15 percent ethanol, approved by the Environmental Protection Agency for use in U.S. vehicles manufactured since model year 2001, may confuse consumers and lead to damaged car engines, the American Automobile Association (AAA) said Friday. E15 contains 15 percent ethanol and 85 percent gasoline

A consumer survey conducted by AAA, the biggest U.S. automobile owner organization, showed that 95 percent of consumers contacted by telephone are not familiar with the standard for the E15, according to Bloomberg. In addition, AAA said that engine damage caused by the ethanol-containing fuel may not be covered under warranties. The U.S. Environmental Protection Agency (EPA) issued the E15 standard in June.

“It is clear that millions of Americans are unfamiliar with E15, which means there is a strong possibility that many motorists may improperly fill up using this gasoline and damage their vehicle,” AAA President Robert Darbelnet said Friday in a statement. “Bringing E15 to the market without adequate safeguards does not responsibly meet the needs of consumers.”

In response to the statement by AAA questioning the use of E15 gasoline, Bob Dinneen, president and CEO of the Renewable Fuels Association (RFA), issued a statement blasting the AAA for being in the pocket of “Big Oil. “(AAA’s) misplaced concern, that E15 should be further tested before being offered for sale, reflects a pathetic ignorance of EPA’s unprecedented test program before approving E15 for commercial use.”

“AAA’s antipathy toward ethanol is well known and tired,” Dineen said. “ When put in contrast to gasoline quality issues AAA continues to ignore, one has to wonder whose interest they’re truly trying to protect, consumers or oil companies?”

In their statement, AAA listed several potential drawbacks associated with the E15 blend including accelerated engine wear and fuel-system damage when used for sustained periods in vehicles not cleared for use.