A new study released today by the Coordinating Research Council says that E15 gasoline, which contains 15 percent ethanol, could damage the engines of certain high-volume car and truck models.

The two-year study was conducted on eight different engines from the 2001 through 2009 model years, with a pair of vehicles for each engine tested--one on conventional gasoline, one on E15.

The 500-hour durability cycle would be the equivalent of roughly 100,000 miles of normal usage, according to the study's author. It monitored cylinder compression, valve leakage and wear, engine emissions, and emissions-control diagnostics.

Two of the eight engines running on E15 suffered lower performance, misfiring, reduced fuel economy, and damaged valves and valve seats. A third showed tailpipe emissions that increased above the legal limit.

The study was conducted by FEV, a consulting firm that has previously worked for the U.S. Environmental Protection Agency. It was initiated by the Coordinating Research Council, which studies the interactions among petroleum products and automotive equipment and is funded by the American Petroleum Institute and eight automakers.

The EPA conditionally approved the use of E15 for cars built between 2001 and 2009 last year.

Ten separate research papers have now been published assessing the impact of raising ethanol content from E10, which all U.S. market vehicles are designed to accept, to E15.

The CRC accuses the EPA of basing its decision to allow the rollout of E15 largely on a study done by the Department of Energy of E15's effects on the durability of catalytic converters. It says the EPA did not wait for all research to be completed before making that decision.

“Our goal is to ensure that new alternative fuels are not placed into retail until it has been proven they are safe and do not cause harm to vehicles, consumers, or the environment,” said Mike Stanton, president and CEO, Global Automakers. “The EPA should have waited until all the studies on the potential impacts of E15 on the current fleet were completed.”

The Association of Global Automakers is a group of car and light-truck makers whose sales constitute almost half of the U.S. market. Its members include Honda, Hyundai, Kia, Nissan, Subaru, Suzuki, and Toyota, along with sports- and supercar makers Aston Martin, Ferrari, Maserati, and McLaren.

BMW, Chrysler, Ford, General Motors, Mercedes-Benz, and Volkswagen are not members of the association.

What should consumers do in the face of these latest results?

If you own a car built before 2001, don't use E15, period. If you own a car built from 2001 through 2009, you can either avoid E15 or dig into the studies and draw your own conclusions--and watch for further news on the topic.

All automakers strongly suggest that you follow their guidance on choosing fuels for your particular model, which can be found in the owner's manual.

Right now, the discussion is somewhat academic.

At present, virtually no E15 is sold in the U.S. because the so-called blender pumps that will dispense it have not yet been installed.

[UPDATE: This article was updated to correct the list of Association of Global Automakers members.]


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