Test Slamming E15 Draws Fire
U.S. Department of Energy official calls out ethanol study that claims E15 blends damage engines.
Published: May 17, 2012
A new report from Coordinating Research Council, says E15 blends can damage engines and offers data that could worry the ethanol industry. The study, apparently funded by the American Petroleum Institute, showed that in some engines mid-level blends of ethanol now being reviewed by the U.S. Environmental Protection Agency could cause problems. But the report is drawing fire not only from ethanol groups but from the U.S. Department of Energy as well.
In a statement titled "Getting it Right: Accurate Testing and Assessments Critical to Deploying the Next Generation of Auto Fuels" Patrick Davis, vehicle technologies program manager, says that the CRC test is "significantly flawed."
Test Slamming E15 Draws FireDavis points out that CRC failed to "establish a proper control group, a standard component of scientific, data-driven testing and a necessity to determine statistical significance for any results."
Here are the points Davis highlighted from the CRC study:
- Instead, only three out of the eight engines were tested with straight gasoline containing no ethanol (E0), and one of those three failed the CRC's test.
- No engines were tested with E10 fuel, the de facto standard gasoline for all grades, which represents more than 90 percent of gasoline available in the U.S. market. Even though E10 fuel has been in the market for over 30 years and is used in all current conventional gasoline vehicles and small non-road engines, it was not part of the CRC test program.
- The CRC also employed a test cycle designed specifically to stress the engine valve train. This test cycle was developed specifically for this study and thus there is no experience base for how to interpret results from the testing.
- The CRC used the arbitrary criterion of 10 percent engine leakdown (a diagnostic test in which an engine cylinder is pressurized with compressed air, and the rate at which the cylinder loses pressure is measured) to determine if an engine "failed." This is not a standard previously employed by either industry or federal agencies during testing, nor as a criterion for any warranty claims. Further, the Energy Department's own rigorous testing has shown that it is not reliable indicator of durability issues.
- Perhaps most surprisingly, the CRC decided to select several engines already known to have durability issues, including one that was subject to a recall involving valve problems when running on E0 gasoline and E10. It is no surprise that an engine having problems with traditional fuels might also "fail" with E15 or E20 ethanol-blended fuels -- especially using a failure criterion chosen to demonstrate sensitivity to ethanol and operated on a cycle designed to stress the valves.
Davis notes that prior to CRC testing, DOE conducted its own "rigorous, thorough peer-reviewed study of the impact of E15 fuel on current, conventional vehicle catalyst systems. The Energy Department study included an inspection of critical engine components, such as valves, and did not uncover unusual wear that would be expected to impact performance." He explains that DOE testing was not designed to be severe service, which can stress valves, but was more geared to a cycle that mirrors every-day driving.
The Energy Department test program was comprised of 86 vehicles operated up to 120,000 miles each using an industry-standard EPA-defined test cycle (called the Standard Road Cycle). The resulting Energy Department data showed no statistically significant loss of vehicle performance (emissions, fuel economy, and maintenance issues) attributable to the use of E15 fuel compared to straight gasoline. The Energy Department test program also showed that 10% engine leakdown is not a reliable indicator of vehicle performance. In the Energy Department program, there were vehicles found to exceed 10% leakdown for all fuels, including vehicles running on E0 and E10. There was no correlation between fuel type and leakdown, and high leakdown measurements did not correlate to degradation in engine or emissions performance.
The American Coalition for Ethanol also responded to the CRC report noting in a statement from Ron Lamberty, senior vice president, that "the real problem here is that people may read about this project and think that it actually has some connection to the real world. The parameters of the test, the definitions of "pass" and "fail" and even the cars selected were carefully chosen to produce the results the study's funders wanted. The Department of Energy points out that this 'study' included engines with known durability issues, and that one of the engines used in the tests even failed the [tests] while running straight gasoline with no ethanol."
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Tagged: EPA, Environmental Protection Agency