Ford lowers fuel economy rating for six vehicles

"The broad implications of this might spur EPA to be more restrictive in how its fuel economy rules and ratings are administered," he added. "This will gain attention in Congress as well."

In the latest case, Ford said it identified an error through internal testing and notified the US environmental regulator. No adjustments on other vehicles are planned after review of the entire lineup, the company said.

The EPA said it conducted independent tests to confirm Ford's results and ordered the company to correct fuel economy labels on the cars within 15 days.

Ford estimated about 200,000 of the affected vehicles had been sold or leased in the United States, and affected owners would receive a "goodwill payment" of up to $1,050 for the estimated difference in fuel costs. Cars in dealer lots will be relabeled with new window stickers reflecting the corrected estimates.

Owners outside the country will be contacted by the automaker.

The largest change is for Ford's Lincoln MKZ hybrid, which saw its combined city and highway fuel economy value reduced by 7 miles per gallon. Other affected models include four versions of the Fiesta, the hybrid and Energi versions of the Fusion, and the C-Max hybrid and Energi.

Ford shares were off 2.3 percent at $16.51 in late New York trading.

Ford's Lincoln brand to debut in China	Ford's 'quality' push comes at busy time for automaker