Gasoline blended with 15% ethanol caused failure in a "substantial" portion of fuel pumps and other components in a test designed to represent 29 million vehicles approved to use the fuel, according to a study the Coordinating Research Council released Tuesday.
The study tested fuel system components such as pumps, dampers, level senders and injectors used in model year 2001-2007 vehicles. Automakers and the oil industry paid for the report.
The US Environmental Protection Agency approved the so-called E15 blend for all cars made in 2001 or later, but some automakers have warned that owners risk voiding their warranties if they use it. The fuel continues to face extremely limited availability in the US since a Kansas marketer first offered it last summer.
The American Petroleum Institute, which wants to dismantle EPA's ethanol mandate, touted the study as another sign that the agency rushed E15 to market before properly studying its risks.
"EPA approved vehicles that were not designed to use E15 -- retroactively saying it's OK to use them," said Bob Greco, API's downstream group director. "We expect going forward that more manufacturers will design and warrant their cars on E15 or some other ethanol blend.
"But EPA made a poor decision in retroactively approving this fuel. They're putting the consumer in the position of: who do they believe? Do they believe the auto manufacturer who designed, built and warranted their cars, or do they believe EPA?"
General Motors approved E15 for models made in 2012 or later, and Ford did the same starting with 2013 models.
The Fuels America Coalition, several trade groups representing US biofuels makers, said the study "displays clear bias" and ignores 6.5 million miles of testing that EPA considered before approving E15.
"The oil industry is intent on maintaining its control over America's fuel supply, and this kind of biased research is exactly why we must continue to protect the Renewable Fuel Standard and the investment it has supported," the biofuels supporters said.
In May, the Department of Energy dismissed an earlier E15 study by the Coordinating Research Council.
"We believe the study is significantly flawed," said Patrick Davis, DOE's program manager for vehicle technologies, adding that it failed to establish a proper control group, set arbitrary criteria and used engines known to have durability problems.
