Hugh Pickens writes "Reuters reports that Hyundai and its affiliate Kia Motors conceded that they overstated the fuel economy on more than 1 million recently sold vehicles, and agreed to compensate owners for the additional fuel costs after the EPA found the errors in 13 Kia and Hyundai models from the 2011 to 2013 model years. The findings were a blow to the two carmakers, which have centered their marketing campaigns on superior fuel economy. The mileage on most labels will be reduced by 1 to 2 miles per gallon, with the largest adjustment being a 6-mpg highway reduction for one version of the Kia Soul, the EPA said. Hyundai previously touted the fact that many of its models get 40 miles per gallon on the highway. Now three Hyundai models, the Elantra, Accent and Veloster, as well as the Kia Rio fall short of that mark, as will the Hyundai Sonata and Kia Optima hybrids."