The EPA said that Ford's original fuel-economy claims for the C-Max Hybrid were overly optimistic. Ford has since revised the hybrid's mileage ratings. Photo credit: Ford Motor Co.

Ford (F 6.10%) landed in trouble earlier this year after some of the company's fuel-economy claims were found to be overly optimistic. After an investigation by the U.S. Environmental Protection Agency (EPA), Ford restated the fuel-economy numbers for its C-Max Hybrid -- and the company is mailing $550 rebate checks to C-Max owners.

That incident led the EPA to launch a larger investigation into automakers' fuel-economy claims. The EPA is said to have run tests on 20 new cars and trucks to see if they lived up to the fuel-economy claims being made by their manufacturers. The final report on those tests is set to be released shortly -- and the word is that several automakers will have some explaining to do.

Will Ford land in hot water with the EPA once again? In this video, Fool.com contributor John Rosevear explains what the EPA is testing, and why -- and offers his take on what could happen if Ford is caught out a second time.