Ford will lower the 47-mpg gas mileage rating for its C-Max Hybrid hatchback, a much-disputed metric that was never backed up by real-world owner experience.

Soon after the cars launched a year ago, widespread media coverage--on this site and Consumer Reports, among others--indicated that owners were getting real-world figures that varied significantly from the rated mileage for Ford's new hybrid models.

Neither the 2013 Ford C-Max Hybrid nor the 2013 Ford Fusion Hybrid, which use identical powertrains, appeared to return nor achieve anywhere near the advertised EPA ratings of 47 mpg combined in real-world use.

According to an exclusive report early this afternoon in trade journal Automotive News, the company had planned an announcement for later today.

Ford declined to comment to that reporter when contacted.

The story did not indicate whether the 2013 Ford Fusion Hybrid or the 2013 Lincoln MKZ Hybrid would be affected as well.

Most owners of other high-efficiency cars, notably the Toyota Prius hybrid, seem comfortable with variation of 10 or 12 percent from EPA ratings.

And a number of Prius owners report average gas mileage higher than that car's EPA-rated 50 mpg.

But Consumer Reports testing found shortfalls of 17 to 21 percent in the two 2013 Ford hybrid models.

And crowd-sourced gas-mileage aggregation sites told the same story.

Comparing the owner-reported mileage on Fuelly to the EPA ratings, it appears that Honda does better than its ratings, Toyota is roughly in line with the EPA numbers, and Ford falls short.

Ford had announced last month it would modify its three 2013 hybrids to boost their fuel efficiency through changes in the cars' vehicle control software.

While automakers may not quote gas-mileage ratings higher than the test results they submit to the EPA, they are free to quote lower fuel-efficiency numbers--though very few do.

We'll update this story if and when Ford releases further details.


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