As impressive as the fuel economy proved to be with the Honda Accord Hybrid, we weren’t surprised that our tested overall mpg figure was significantly lower than the official EPA rating. We’ve consistently seen high mpg hybrids falling short of EPA testing—in our results and in “real life” driving. Reviewing the data for the true hybrids currently in our ratings, among the 19 cars, only three show a bigger discrepancy than the Accord Hybrid: the hybrid versions of the Ford Fusion, Lincoln MKZ, and Volkswagen Jetta.
Understandably, different test results will yield different results, but there remains a consistent schism here. Faced with gasoline prices hovering near $4 a gallon, consumers are naturally placing a priority on fuel economy in choosing their next car. Often, the final car choice is tipped in a direction by the mpg indicated on the window sticker. And as our tests have shown, owners may not be experiencing the same fuel economy promised on the sticker and in advertising.
With the Honda Accord Hybrid, potential customers see the EPA citing 47 mpg overall, broken down to 45 mpg city and 50 mpg highway. A reasonable car shopper would then assume that no matter what their personal mix of driving may be, it would be safe to assume mileage would be 45 mpg or higher. We recorded an excellent 40 mpg overall in our tests—impressive for a midsized sedan, putting the Accord Hybrid in an exclusive, efficient club. But it isn’t the 47 mpg that the government touts. Even owners on the official fueleconomy.gov website are reporting 42.4 mpg on average.
As the chart illustrates, there are always some differences in the test results. Among this group, there is just a single case where our results were greater than the government’s: the Honda CR-Z.
Our results from the Ford C-Max Hybrid fuel economy test that showed 37 mpg overall, a dramatic 10 mpg less than the 47/47/47 mpg EPA rating. Ultimately, Ford drove its hatchback through a fuel economy labeling loophole, and it has since revised the car and the rating. (Read: “Why Do Ford's New Hybrids Ace the EPA Fuel Economy Tests?”)
The reason for the discrepancy boils down to the ways the Consumer Reports and EPA highway test methodologies differ. In the Consumer Reports highway test, we record the average fuel usage in two directions at a steady 65 mph on a specific section of highway. In contrast, the majority of the EPA highway cycle simulates a vehicle traveling mostly at speeds below 55 mph. Although the EPA tests reach 80 mph at times, the highway tests include a fair amount of gentle acceleration and coasting. Speeds average only about 48 mph. Of course, it is possible to design cars to the test. (Learn more about how Consumer Reports tests cars.)
But in the time since the report last fall on Ford, the EPA has not made significant changes to how it tests and shares information on hybrids. We discussed the matter with the agency last year and still await changes that will better match real-world performance with the official numbers automakers are required to use for labeling and marketing.
Until then, be skeptical of EPA estimates and automakers’ claims that appear too good to be true. And, as always, check our ratings and the experience of owners before buying.
—Jeff Bartlett
Consumer Reports has no relationship with any advertisers or sponsors on this website. Copyright © 2006-2014 Consumers Union of U.S.
