HispanicBusiness

Korean car manufacturers Kia and Hyundai will lower their fuel economy ratings on several of their current models after an investigation by the US Environmental Protection Agency (EPA) found that the companies had overstated their fuel efficiency.

Both manufacturers, whose products are known for their claim to fuel-efficiency, apologized on Friday and offered to make up the financial difference for car owners.

"Following up on the EPA's audit results, we have taken immediate action to make the necessary rating changes and process corrections," said WC Yang, chief technology officer of Hyundai/Kia research and development.

The two companies are closely linked under the Hyundai Motor Group.

On average, the EPA found that both companies had overstated their efficiency by an average of 3 per cent. For the 2012 KIA fleet, this means a downgrade from 27 miles per gallon (mpg) to 26 mpg. In metric system terms, it means the fleet uses 9.6 litres per 100 kilometres instead of the claimed 8.7 liters.

Both companies said they will adjust the fuel economy rating on all of the affected 2011-2013 models, about 900,000 cars.

Current and former customers will receive a reimbursement to cover the additional fuel costs caused by the incorrect fuel ratings. Car owners will receive debit cards based on how far they've driven the car and on fuel costs in their area.

In an apparent bid to keep the loyalty of customers, the companies will sweeten the compensation with an additional 15 per cent on top of the reimbursement.

The EPA launched its investigation after the agency received a number of consumer complaints about Hyundai mileage estimates. The investigation was later expanded to include Kia models as well.

"Consumers rely on the window sticker to help make informed choices about the cars they buy," said Gina McCarthy, a spokeswoman for EPA. "EPA's investigation will help protect consumers and ensure a level playing field among automakers."

It is unclear yet if the car manufacturers will have to pay fines for posting misleading information.