Automakers and the oil industry released a report today that casts doubt on the safety of gasoline containing 15 percent ethanol and shows that at least some engines running the fuel suffered damage during recent testing.
But ethanol backers and the Obama administration immediately countered that the study was fundamentally flawed, because it used engines with known durability issues” and didn’t include control group testing of the 10 percent ethanol blend that is now the standard at filling stations nationwide.
The dispute is the latest round in a long-running fight over the 15 percent ethanol fuel blend known as E15. A 2007 energy law mandated 36 billion gallons of renewable fuels be used by 2022, and the Environmental Protection Agency in 2010 approved the sale of E15 for model year 2001 and newer cars and light trucks. The agency did not clear E15 for use in older vehicles, boats or other devices, such as lawn and garden equipment.
In the new oil industry and automaker-funded study, the not-for-profit Coordinating Research Council tested eight specific engines (28 in all) from vehicles spanning model years 2001 through 2009. Researchers ran the engines for 500 hours under conditions representing about 100,000 miles of driving while fueling them with ethanol-free gasoline, the E15 blend containing 15 percent ethanol and a variety comprising 20 percent ethanol.
Two of the eight engines showed damage while running on E15, according to the study. Specifically, both of those auto engines showed leaking cylinders. Subsequent analysis by their original manufacturers revealed damage to intake valve seats, possibly causing the leakage.
One of the eight engines running E15 also failed emissions tests.
American Petroleum Institute President Jack Gerard said that the study results reveal millions of cars are at risk of damage from E15.
“Not all vehicles in the CRC tests showed engine damage, but engine types that did are found in millions of cars and light duty trucks now on America’s roads,” Gerard said. “We believe there’s at least as a minimum, 5 million that are subject to damage as a result of this rule, and we believe that is a conservative estimate.”
Automakers said the metallurgy and makeup of the engines that had valve leakage could foreshadow problems with similar vehicle engines, including some just now rolling off the assembly line.
Federal regulators and ethanol boosters panned the study. In a blog post, the Department of Energy, which conducted its own testing before the EPA approved E15 in 2010, provided a laundry list of criticisms:
- None of the engines were tested with E10, which would have provided a better baseline for comparison, since it is the “de facto standard” representing more than 90 percent of gasoline available in the U.S. market. Instead, the vehicle engines were run on E20, E15 and an ethanol-free gasoline.
- The engine test cycle, which was designed specifically for this study, was specifically designed to stress the engine valve train. Since the test method hasn’t been used in other studies, there’s no clear way to interpret the results, the Energy Department said.
- The standard for measuring engine leakdown — and deeming it as having “failed” — is not a standard used by automakers and federal agencies for warranty claims or other uses.
The Energy Department also said the study included “Several engines already known to have durability issues, including one that was subject to a recall involving valve problems” when running on E10 and ethanol-free fuels. “It is no surprise that an engine having problems with traditional fuels might also fail with E15 or E20,” the Energy Department said.
Bob Dinneen, the president of the Renewable Fuels Association, characterized the study as misleading.
“By funding research using questionable testing protocols and illegal fuels, the results of this study are meaningless,” Dinneen said. The study results “only serve to further muddy the waters and shun the overwhelming desire of 75 percent of Americans for greater choice at the pump.”