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E15 ethanol fuel can damage auto engines

07.01.2012  |  Thinnes, Billy,  Hydrocarbon Processing Staff, Houston, TX

Keywords: [ethanol] [gasoline] [consumer] [EPA] [gas station] [fueling] [misfueling] [engines] [damage]

Auto repair costs for consumers could rise due to adverse effects of fuel containing 15% ethanol blends (E15), according to new results from a two-year study on engine durability.

The study was conducted by FEV, a longtime consultant to the US Environmental Protection Agency, on behalf of the Coordinating Research Council (CRC).

The CRC study showed adverse results from E15 use in certain popular, high-volume models of cars (Table 1), its authors said.

Problems included damaged valves and valve seats, which can lead to loss of compression and power; diminished vehicle performance; misfires; engine damage; poor fuel economy and increased emissions.

“Clearly, many vehicles on the road today are at risk of harm from E15. The unknowns concern us greatly, since only a fraction of vehicles have been tested to determine their tolerance to E15,” said Mitch Bainwol, CEO of the Auto Alliance trade group.

“Automakers did not build these vehicles to handle the more corrosive E15 fuel. That’s why we urged EPA to wait for the results of further testing.”

The potential costs to consumers are significant, the study says. The most likely repair would be cylinder head replacement, which costs from $2,000-$4,000 for single cylinder head engines and twice as much for V-type engines.

“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, CEO of the Global Automakers trade group. “The EPA should have waited until all the studies on the potential impacts of E15 on the current fleet were completed.”

“Automakers believe that renewable fuels are an important component of our national energy security, but it is not in the longer term interest of the government, vehicle manufacturers, fuel distributors or the ethanol industry itself to find out after the fact that equipment or performance problems are occurring from rushing a new fuel into the national marketplace,” added Bainwol.

Growth Energy, an ethanol industry trade group, petitioned the EPA in March 2009 to raise the limit on ethanol in gasoline from 10% to 15%.

In June 2008, EPA outlined testing needed for the agency to approve a waiver, and EPA requirements were consistent with test plans developed by the auto and oil industries.

The CRC, composed of engineers from the auto and oil industries, was working with EPA and US Department of Energy (DOE) on a multi-year suite of tests on the effects of higher blends of ethanol, according to the trade groups.

This testing included more than $14.5 million of research sponsored by the auto and oil industries, and $40 million of testing sponsored by the federal government.

Before those tests were completed—in October 2010 and January 2011—the EPA granted “partial” waivers to allow the introduction of E15 into the marketplace for use in model year 2001 and later vehicles.

EPA’s decision was based largely on a DOE study of the effects of E15 on durability of catalytic converters, the primary pollution control system in a vehicle

EPA did not undertake or wait to consider the results of this engine durability test, or for other E15 related research still underway, the groups allege.

The CRC study took duplicates of eight different vehicle model engines spanning the 2001–2009 model years. All 16 vehicles were tested over a 500-hour durability cycle corresponding to about 100,000 miles of vehicle usage, the authors said.

A range of engine operating parameters was monitored during the test, including cylinder compression, valve wear, valve leakage, emissions and emissions control system diagnostics.

Two of the engines tested on E15 were said to have mechanical damage. Another engine showed increased tailpipe emissions beyond the allowable limit.  HP

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Karim Rahimi- Khamnei

A Turkish proverb says: every beautiful has a flaw.


It would be interesting and valuable to have a comparison of the engines referred in the article and those mentioned by Westhoff. Assuming both results are accurately described there has to be physical reasons for the differences.

Keith Bowers

Increasing ethanol level to 15% will further reduce fuel economy, which is not 'advertized on the pump' as it should be. Some vehicles ECM system may reach mixture tuning limits and require re-programming. Engine durability should not be impacted IF the proper lube oil is used and changed appropriately more often.
The biggest concern is the potential for lots more 'splash blending' to much higher than 15% Ethanol--which will definitely damage some engines and emission control catalysts.

Carl Westhoff

I would advise the engineers from the US automakers to come to Brazil for an update.
We have been using gasoline with up to 25% anhydrous ethanol since WWII. Until the sixties that mixture was used in cars imported mainly from the USA. They were expensive and they were suposed to last for years and they did. One of the beneficial effects of the ethanol is that it improved the octane rating of the fuel that was lousy at that time. Important: as long as the mix were not changed we had no problems.
In the eighties a major part of the Brazilian car fleet started burning 100% hydrated ethanol. We had some probems with corrosion, but these were solved in due time and now ethanol is the choice fuel when its price is competitive with gasoline.
Presently, more than half of the cars sold in Brazil can burn either gasoline or ethanol or a mixture without any change in tunning. We simply fill the tank with the fuel of choice and the electronics take care of it. No problems.
I myself had a Ethanol VW Santana that stayed with me for 13 years, 200,000 mi. with none of the reported problems. Presently I own a multifuel Fiat and I expect no problems either.

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