American Petroleum Institute President Jack Gerard said testing by the Coordinating Research Council found the use of E15 -- gasoline containing 15 percent ethanol -- could damage vehicle engines.
The U.S. Environmental Protection Agency last month announced it approved the first applications for the use of E15. Gerard said the EPA went ahead with the E15 program even though vehicle testing hadn't been completed.
"The (CRC) tests provide strong evidence E15 could damage the engines of many cars and light trucks," Gerard said in a statement.
The EPA said E15 is permitted only in vehicles manufactured after the 2011 model year and in off-road vehicles. The agency noted its decision wasn't a mandate for the use or sale of E15.
"The results of just completed engine testing of E15 by the Coordinating Research Council confirm that EPA did not perform due diligence and moved too quickly in its E15 vetting process," said Gerard.
The API is one of the members of the CRC, alongside major automobile manufacturers such as Honda, Ford and Volkswagen.