According to a statement released on Saturday, the EPA will review data from Consumer Reports’ tests of the Ford hybrids, in which both hybrids fell well short of the 47 mpg earned in all three EPA categories (city, highway, combined).
Consumer Reports says its most accurate numbers for the C-Max are 35 mpg city, 38 mpg highway, and 37 mpg combined. The Fusion scored 35 mpg city, 41 mpg highway, and 39 mpg combined.
Green Car Reports also noticed a discrepancy in the Fords’ mpg numbers. It could only get 40 mpg out of the C-Max Hybrid.
The EPA did not say what form its investigation would take or, as is the case with Hyundai and Kia, it would consider penalizing Ford. The agency did say that it believes the variability inherent in switching back and forth from gasoline to electric power might be the source of the problem.
“There’s absolutely no doubt: A hybrid is going to be far more variable than a conventional vehicle,” Linc Wehrly, director of light-duty vehicle center compliance at the EPA’s Ann Arbor, Michigan laboratory told the Detroit News.
Ford agreed; a spokesman said the company has received varying mileage reports from customers, including some above 47 mpg, depending on driving style and driving conditions.
Consumer Reports says the Toyota Prius got six fewer mpg in real-world testing, and Car and Driver says the Camry Hybrid also missed the EPA mark in its tests.
However, the EPA’s own survey of consumers still show a bit of a discrepancy. On its Fueleconomy.gov site, the EPA allows owners to post their mileage, and displays the average next to the official mpg ratings.
As of this writing, the C-Max Hybrid was rated at 39.4 mpg, based on results from 33 owners. The Fusion Hybrid scored 40.6 mpg, based on 15 owner reports. Both groups included vehicles from different states with roughly equal amounts of city and highway driving.
The Prius, rated at 50 mpg combined, is currently scoring 51.1 mpg in the real-world survey. The Camry Hybrid is rated at 40 mpg combined, and is currently scoring 39.8 mpg.
Depending on the results of its investigation, the EPA could force Ford to lower its mpg ratings, taking away a significant selling point for the Blue Oval’s wares. Ford could also find itself in the same position as Hyundai and Kia, who are compensating owners that bought cars with inflated mpg claims.