AAA is calling for the Environmental Protection Agency (EPA) to reject a petition that would increase the permissible content of ethanol blended in gasoline to 15 percent, or E15, from the currently allowed 10 percent, commonly known as E10.
"While AAA supports the integration of alternative fuels into the nation's fuel supply, additional data is needed on the potential impact associated with the use of E15 gasoline over time on the country's vehicle fleet," says AAA Vice President of Public Affairs Kathleen Marvaso. "Therefore, AAA is opposed to increasing the ethanol content in gasoline to 15 percent without unbiased, objective research first proving that E15 will not damage engine systems and component parts, compromise vehicle performance and fuel efficiency, or increase vehicle emissions."
Specific areas of concern
After reviewing the petition, AAA identified the following areas of concern:
• Potential negative impact on vehicle exhaust emissions - There are substantial concerns about increased NOx output that is likely to result from increased cylinder temperatures generated by leaner air/fuel ratios under certain operating conditions.
• Degradation of engine operability in cold start-up conditions - Most vehicle systems operate from factory calibrated parameters until the vehicle engine and exhaust systems reach a temperature sufficient to support full feedback operation. The increased oxygen content of E15 could cause a stalling or stumbling condition before the engine reaches the minimum temperatures needed to support feedback. Engine system reprogramming could mitigate the issue, but would not be applicable to all vehicles and would be a major cause of inconvenience and cost to vehicle owners whose vehicles are capable of being reprogrammed.
• The potential to cause catastrophic engine damage - Modern fuel systems are designed to flow sufficient fuel to the engine within the vehicle's design parameters. AAA believes there could be the potential for damage to some engines (specifically, high output naturally aspirated and forced induction engines). AAA does not believe this would be a widespread problem but for those impacted, the damage would be significant.
• System component damage - The increase in ethanol would reduce the lubricity of the fuel and could noticeably increase the wear on key fuel system parts including the fuel pump and fuel injector seats. This potential side effect is most insidious since it could take years to realize the full extent of damage.
• Older vehicles are not designed to run on ethanol and would unquestionably experience poor drivability and reduced engine reliability - These vehicles do not use an oxygen sensor to monitor exhaust oxygen content and would undeniably run lean. This affects drivability and increases NOx emissions. Some of these vehicles are collector cars, but many are owned by Americans who can't afford a newer vehicle. E10 has been a problem for these motorists and E15 would make it worse.
• Catalytic converters could be impacted by the increased temperatures caused by the higher alcohol content in the fuel - This could shorten the expected life of a converter and increase emissions far beyond any saved by the use of increased alcohol in the fuel. Shortening the life of a catalytic converter would create serious economic consequences for those affected and could increase overall emissions.
• Vehicle warranty and service agreement issues - The potential for significant vehicle warranty and service agreement issues as a consequence of damage incurred due to use of E15 fuel.
• E15 will reduce the fuel efficiency of the vehicles in which it is used - The lower fuel economy combined with depressed residual value will substantially increase the costs associated with owning and operating a vehicle.
For more information, visit www.aaa.com.
