UAI: Test fuels are not representative of real-world fuels

By Matt Thompson | January 23, 2019

An analysis commissioned by the Urban Air Initiative raises questions about studies used by U.S. EPA to model ethanol’s emissions.

The independent analysis, completed by Future Fuel Strategies, looked at nearly 100 vehicle emissions studies, and concluded that the test fuels used often do not match the real-world fuels available to consumers. Many of the studies that were analyzed are used by EPA to model ethanol emissions and were published by the Coordinating Research Council, which is supported by the petroleum industry.

According to the analysis, in many of the studies, test fuels were match blended to meet certain specifications. Meeting those specifications requires the addition of toxic aromatics to the test fuel, beyond what is found in the gasoline that consumers are using. “All we’re saying is we need to start making test fuels that represent what the refineries are doing,” said Steve Vander Griend, technical director for UAI.

This is not the first time these study methods have been called into question, but what is new, according to UAI, is that outside fuel experts with experience in refineries, emissions and vehicle emissions modeling contributed to the analysis.

While the issue has been brought to light before, UAI Director Trevor Hinz said the new analysis does more to explain why the studies are flawed. “The consultants went deeper down into the weeds and said, ‘Well, why doesn’t it work? What’s going on behind the scenes to cause this data to be generated that’s not accurate, that doesn’t reflect what’s going on in the real world in consumer fuels that are being purchased today?’”

Hinz said UAI hopes to have input on how emissions tests are conducted in the future. “It seems like the EPA only works with the refiners and the petroleum industry when it comes to test fuels and modeling emissions from test fuels, and I think it’d be a big step forward if we could just get a seat at the table when they’re putting these programs together and blending the fuels and running the tests,” Hinz said.

Vander Griend agreed. “There is no guideline [for test fuels] yet today,” Vander Griend said. “That’s what we hope would be the next phase, is actually to create the guidelines, so that the people who are doing the research—who are not fuel experts—will have a better understanding of how to best model the emissions.”