In the NYT's article "Hyundai and Kia Acknowledge Overstating the Gas Mileage of Vehicles", it also says:
Hyundai and Kia apologized to customers for what they called “procedural errors” in testing that resulted in incorrect mileage stickers on some of their most popular models, like the Hyundai Elantra and Kia Rio...
The companies said the misstated mileage figures were a result of internal errors in testing the vehicles for E.P.A. certification.
I don't know how results in testing that were thought to be true equates to the sentiment that the companies somehow exaggerated the numbers more than what was known to be true.
The headline I like more is "Hyundai and Kia Acknowledge Errors In Gas Mileage Performance Data".
On their Web site, Hyundai says to its customers "We’ve got your back" in regard to its program to adjust its stated fuel economy rates and reimburse customers (approximately 900,000 owners) the difference between the previously stated fuel ratings and the new fuel ratings (more about the program in the press release).
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