At a press conference this afternoon, Ford announced it would reimburse current owners of model-year 2013 C-Max vehicles $550 for a 4-mpg difference in its EPA combined city/highway mileage. Lessees will receive $325. Further updates for the 2014 C-Max could raise mileage beyond 43 mpg, which applies to the 2013 C-Max only.
Ford says it voluntarily rerated the 2013 model because the current car matches the Fusion Hybrid's mileage under the EPA's "general label rules." Raj Nair, Ford's group vice president of global product development, told reporters those rules date "back to the 1970s, and they were created by the EPA as a general means to provide fuel economy labels without having to test every single vehicle in the industry." Most cars are rated using this rule, Nair said.
As we reported in November 2012, that policy allows the EPA and automakers to rate cars with common weight and drivetrain characteristics under the same mileage label — but it can be problematic, as in this case where "combining sedans like the Fusion Hybrid with crossover utility vehicles like the C-Max hybrid under a single, general label could result in anomalies," Nair said.