Are Ford’s fuel consumption numbers for the Fusion Hybrid and C-Max Hybrid over-hyped by the manufacturer?

Ford has been clamoring from one press release to another that this duo of hybrid vehicles is rated at “47 city/47 highway/47 combined mpg.”

Consumer Reports has doubts as it has not been able to get close to these claims.

Among current models, more than 80 percent of the vehicles the magazine tested are within 2 mpg of the official EPA figures.

As Consumer Reports stated, “The largest discrepancy we’ve previously seen was 7 and 6 mpg for the Toyota Prius C subcompact and Prius hatchback, respectively.”

But now, in its tests, the magazine saw numbers being close to 20 percent off.

In the magazine’s own words: “the Fusion Hybrid delivered 39 mpg overall and 35 and 41 in city and highway conditions, respectively. For the C-Max Hybrid, we got 37 mpg overall, with 35 and 38 for city and highway. These two vehicles have the largest discrepancy between our overall-mpg results and the estimates published by the EPA that we’ve seen among any current models.”

How the magazine measures a vehicle’s mpg can be found here. In short, they buy a car off a dealership lot and drive it for at least 2,000 miles before doing any testing. Then they install a precise fuel meter and follow a set driving route on their test track.

While the magazine’s staff praises both vehicles, they can’t understand the discrepancy between the official EPA figures and their results. While it is clear that by their nature, hybrid vehicles show more difference in their fuel consumption depending on the driver, the U.S. Environmental Protection Agency is taking the issue seriously and will be reviewing the magazine’s data.

This fuel consumption controversy comes not long after the Hyundai / Kia duo has been forced by the EPA to adjust the mpg ratings of many of its models.

Consumer Reports, Automotive News