Korean automakers Hyundai and Kia will pay the U.S. government a record $100 million penalty for overstating gas mileage figures on many of their vehicles. According to the Environmental Protection Agency, the cars were labeled with incorrect gas mileage -- the window stickers overstating fuel economy figures by between one and six miles per gallon. The Justice Department and the EPA announced Monday that on top of the settlement, Hyundai and Kia will spend $50 million to arrange third party contractors to certify mileage claims in the future. The two Seoul based automakers, which share manufacturing but market separately in the U.S., have also agreed to give up a combined $200 million in greenhouse gas emission credits. They have started a program to reimburse drivers on the additional gas they didn't expect to burn. The vehicles involved include the Hyundai Accent, Elantra, Veloster and Santa Fe and the Kia Rio and Soul.