We'd heard that Kia had been sending out replacement window stickers for certain models, and now we know why: Hyundai Motor America and Kia Motors America overestimated the fuel economy numbers for 900,000 cars.

Accent, Veloster, and Elantra models (and their Kia counterparts) Hyundai had claimed would get 40 mpg have been reduced by the EPA to 37 or 38 mpg, as The Detroit News learned. They're trying to correct the mistake by reimbursing customers, although it will likely be only about $100 for a customer who drove 15,000 miles in a year.

That means two things for the Korean automaker. First, they're not the number one producer of 40 mpg vehicles as they'd asserted. Second, this more than doubles the number of vehicles EPA has had to downgrade since 2000.

This is quite the smudge on the reputation of a company that attracts customers with low cost, fuel efficient vehicles. Especially now, during a period of economic hardship.

If you have a Hyundai go here, if you have a Kia go here.

Photo credit: Hyundai

Hyundai-Kia Forced To Change Fuel Economy Numbers, Will Reimburse Car OwnersS