Hyundai and Kia today announced that the companies are revising their fuel economy estimates downward after the EPA spot-checked several models and found that the results did not live up to Hyundai's and Kia's claims.
The fuel economy figures are off by an average of 3 percent, according to a press release issued by the two automakers. The biggest error came in highway mileage for the Kia Soul Eco, which is now down from 35 mpg to 29 mpg.
"I sincerely apologize to all affected Hyundai and Kia customers, and I regret these errors occurred," said W. C. Yang, chief technology officer of Hyundai/Kia research and development. "Following up on the EPA's audit results, we have taken immediate action to make the necessary rating changes and process corrections."
The errors were discovered in the EPA's lab tests, which measure car's fuel economy on a dynamometer (treadmill), and in a closed-track coast-down test. Incorrect procedures by Hyundai in the coast-down test lead to too little resistance on the dynamometer, and thus inflated fuel economy claims. EPA retested the cars based on complaints from consumers who said they did not get the advertised fuel economy. Many of the complaints centered around the Hyundai Elantra, which the company claimed in ads returned 40 mpg on the highway.
In Consumer Reports' own real-world fuel economy tests, we also found the Elantra could only muster 39 mpg on the highway and 29 mpg overall. That's unusual, given that many cars beat their EPA high rating. Our fuel economy ratings are independent and unaffected by the revisions.
We have found that the latest crop of Hyundais and Kias have been more competitive in our tests, but not necessarily class leaders.
Hyundai will issue customers debit cards, crediting them for the estimated additional fuel costs based on the actual miles drive, plus 15 percent.