2013 Ford C-Max Fuel Economy Adjustment
Ford's 2013 C-Max Hybrid just got its estimated fuel economy slashed to 43 mpg. The company says it will compensate owners and leasers for the change. C-Max photo: Ford Motor Co.

Ford Motor Co. (NYSE:F) will pay owners of its C-Max hybrid a $550 “goodwill payment” after revising its fuel economy value from 47 miles per gallon to 43 mpg.

Here’s what Ford said after markets closed in New York on Thursday:

“Because this voluntary step results in miles-per-gallon values different from the original C-MAX Hybrid label, Ford … is making a goodwill payment to current C-MAX Hybrid owners for the estimated average fuel cost of the difference between the two labels. Customers who purchased their vehicle will receive a check from Ford for $550. Customers who leased their vehicle will receive a check for $325.”

In December, Consumer Reports said the labeled fuel economy of the hybrid version of Ford’s compact that went on sale in the 2012/2013 model year was off by about 10 miles per gallon. Instead, it said the 2013 C-Max Hybrid and the 2013 Ford Fusion Hybrid are closer to the economy of the Toyota Prius, the top-selling hybrid, than Ford has initially estimated. Ford appears to still be standing its ground on the Fusion economy.

The news led the Environmental Protection Agency to announce it would be reviewing the fuel economy of the two models, and Ford’s announcement, which came Thursday after markets closed in New York, could be an effort to appear proactive rather than waiting for the government to issue a decision on the veracity of the company’s fuel efficiency claims.

"Ford wouldn't take such a drastic step if it didn't feel that it was absolutely necessary, even if it's just a move to protect its image,” said John O’Dell, green car analyst for the online automotive information provider Edmunds.com. “Edmunds.com's own testing found that the 47 mpg mark is achievable in the C-Max, but that was under controlled driving conditions.”

Ford insists that its fuel economy estimates are “consistent with EPA’s General Label rules,” but that the C-Max’s estimates were based on the results for the Ford Focus Hybrid, which was then extended to “a family of vehicles.” In other words, it didn’t test the C-Max separately.

Ford points out that the C-Max Hybrid still tops the Prius in fuel economy. The Prius gets 42 miles per gallon. Ford delivered 2,700 C-Max units in the U.S. in the first seven months of 2013.