Ford lowers fuel economy ratings for six vehicles, promises compensation

Lincoln MKZ loses 8 mpg highway. Other revisions affect Fiesta, Fusion, C-Max.

Ford has lowered its fuel economy ratings for six different vehicles, dropping some estimates by as much as 8 mpg from previously published figures.

The revisions mostly affect traditional hybrids and Energi plug-in editions for the 2013 and 2014 model years, though the 2014 Fiesta is also included on the list.

The Lincoln MKZ Hybrid was the hardest hit, with city/highway/combined ratings falling from 45/45/45 mpg to 38/37/38 mpg. The Ford Fusion Hybrid was second on the list, shaving 3 mpg from its city rating and 6 mpg from its highway efficiency. The C-Max Hybrid was revised with a 3 mpg drop for each scenario.

The plug-in ratings were also reduced, both for electric-only range and mpg during gasoline operation. Both the C-Max Energi and Fusion Energi drop from 43 mpg to 38 mpg, with EV range lowered from 21 miles to 19 miles.

Ford claims to have discovered an error with its "total road load horsepower" (TRLHP) resistance levels used in dynamometer tests to determine fuel economy estimates. The company also erroneously correlated its wind-tunnel observations to the TRLHP model, further inflating the mpg figures.

"We apologize to our customers and will provide goodwill payments to affected owners," said Ford CEO Alan Mulally. "We also are taking steps to improve our processes and prevent issues like this from happening again."

Compensation varies between models, with the highest payouts for owners and lower payments for lease customers. The company will send $1,050 to Lincoln MKZ owners, $850 for the Fusion Energi, $775 for the C-Max Energi and Fusion Hybrid, $475 for the C-Max Hybrid, and $200 to $450 for Fiesta owners.