Check Engine Soon: E15 Fuel Blend Puts Cars at Risk


Phoenix, Nov. 30, 2012. A recent survey by AAA finds a plethora of problems with E15 gasoline. The new fuel blend, which comprises 15 percent ethanol and 85 percent gasoline, was approved by the Environmental Protection Agency (EPA) earlier this year.


“As an advocate for the motoring public, AAA supports the development and use of alternative fuels,” said John Walter, director of automotive repair for AAA Arizona. “However, E15 is plagued with a variety of problems, from consumer confusion and the potential for voided warranties to potential vehicle damage.”


Consumer Confusion

According to a recent AAA survey, an overwhelming 95 percent of consumers have not heard of E15. In addition, nearly half (44 percent) said they did not know if the fuel was approved for use in their primary vehicle.


Manufacturer Warning
The number of vehicles approved to use E15 – only about 12 million out of the more than 240 million light-duty vehicles – is limited, while the use of the fuel blend in non-approved vehicles can compromise a vehicle’s warranty:  

  • Less than 5 percent of cars on the road are approved by automakers to use E15. Approved vehicles include flex-fuel models, 2001 model-year and newer Porsches, 2012 model-year and newer GM vehicles and 2013 model-year Ford vehicles.
  • Five manufacturers (BMW, Chrysler, Nissan, Toyota and Volkswagen) say their warranties will not cover fuel-related claims caused by the use of E15.
  • Seven additional automakers (Ford, Honda, Hyundai, Kia, Mazda, Mercedes-Benz and Volvo) have stated that the use of E15 does not comply with the fuel requirements specified in their owner’s manuals and may void warranty coverage.

Experts Raise Red Flag

What’s more, after reviewing available research, AAA automotive engineering experts believe that sustained use of E15 in both newer and older vehicles could result in significant problems such as accelerated engine wear and failure, fuel-system damage and false “check engine” lights for any vehicle not approved by its manufacturer to use E15.

“Additional testing needs to be done to determine the impact of E15 on vehicle engines and fuel system components,” Walter said. “Until this happens, AAA urges consumers to follow the recommendations of manufacturers to protect themselves from voided warranties or potential damage from this fuel blend.” 


This summer, the EPA officially approved the sale of E15 after receiving a waiver request from producers interested in expanding the use of corn-based ethanol. Despite objections by auto manufacturers, the EPA approved the use of E15 gasoline in flex-fuel vehicles and 2001 model year and newer cars, light-duty trucks and medium-duty passenger vehicles and SUVs. Currently, at least 10 gas stations in three states (Kansas, Iowa and Nebraska) sell E15, but that number is expected to grow.


The survey findings related to consumer knowledge of E15 are from a AAA telephone survey conducted among a national probability sample of 1,012 adults comprising 504 men and 508 women 18 years of age and older, living in private households in the continental United States


As an advocate for the motoring public, AAA monitors gas prices and emerging fuel blends, such as E15. For more information, visit


AAA Arizona, the Arizona affiliate of AAA, provides automotive, insurance and travel services to more than 825,000 Arizona members. Annually, AAA’s Roadside Assistance responds to more than 450,000 calls for help on Arizona roadways. The auto club also provides insurance, travel, auto repair, discounts and financial services to AAA members. Since its founding in 1927, AAA Arizona has been a leading advocate for the safety and security of all travelers.