Others pass tests that tripped Hyundai, Kia
EPA has replicated results of key test since '10
Vehicles from Honda and other automakers passed the same EPA tests that revealed Hyundai and Kia had overstated their fuel economy ratings on 13 nameplates in the 2011-13 model years, industry sources say.
The EPA this month ordered the two Korean brands to relabel the affected vehicles with lower fuel economy numbers.
Hyundai and Kia, which face lawsuits and will voluntarily spend millions of dollars reimbursing customers for extra fuel, said the errors stemmed from how engineers in Korea conducted the "coast down" test, a main step used to calculate U.S. fuel economy.
Industry sources say the EPA has replicated the coast down test since 2010 to check more than a half dozen automakers' math.
The companies include Honda North America Inc. and Toyota Motor North America Inc., both of which confirmed the audits to Automotive News.
Honda says the EPA told the company it was satisfied with fuel economy claims for the 2011 Accord and 2012 Civic.
"Our numbers did check out," said Edward Cohen, vice president of government and industry relations.
Coast down tests
The EPA conducted coast down tests to verify fuel economy numbers for two Toyota vehicles as part of the same round of audits, a company spokeswoman said.
Toyota has "not heard officially of the outcome" of those tests, but executives "have confidence in the methodology Toyota uses to derive its values," she said.
Several other major automakers declined to comment. The EPA has said its investigation will continue and that it doesn't believe Hyundai and Kia's problems extend industrywide, but it has declined to comment further.
John German, who worked 13 years at the EPA's vehicle testing center in Ann Arbor, Mich., between stints at Chrysler and Honda, said he wasn't surprised when he learned that the coast down test was the source of Hyundai and Kia's errors.
The test measures how far a speeding vehicle rolls once it is put into neutral. The resulting calculation, known as "road load," reflects the vehicle's aerodynamics, the resistance of its tires and the friction at various points throughout the drivetrain.
That calculation goes into the dynamometer test used to estimate miles per gallon, so a vehicle with an enhanced "road load" score will show better fuel economy despite performing no better on the dynamometer test.
The EPA has not always replicated coast down tests to confirm the numbers submitted by automakers. German said the agency stopped doing that about 20 years ago, while he worked there, because investigators had not found any errors in road load calculations after years of tests.
The new corporate average fuel economy rules that became final in 2010 may have been the impetus for a new round of audits.
"If you have stringent standards, it dramatically increases the motivation to try to meet those standards any way you can," said German, a senior fellow at the International Council on Clean Transportation.
After the recent enforcement rush, it should be sufficient for EPA to do coast down tests for just a few vehicles per year, German said, because automakers "can see from the Hyundai case that the consequences of being wrong are very severe."
You can reach Gabe Nelson at email@example.com.