DETROIT Ford Motor Co's (F.N) C-Max and Fusion hybrids fell about 20 percent short of its fuel economy claims, Consumer Reports magazine said after running tests on both models.
The influential magazine said the Fusion hybrid delivered 39 miles per gallon both on the highway and in city driving, while the C-Max hit a combined 37 miles per gallon. Both models were expected to achieve about 47 miles per gallon, according to estimates from Ford and the Environmental Protection Agency.
"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," Consumer Reports said in a blog post on its website.
Improving the fuel efficiency of its lineup has been a pillar of Ford's strategy for the past six years. The No. 2 U.S. automaker expects to wind up with 11 percent of the U.S. market for electrified vehicles this year.
Ford must also meet the U.S. government's target for corporate average fuel economy of 54.5 mpg by 2025, which translates to 36 mpg or higher in real world driving.
Driving aggressively and other factors can undercut the fuel economy estimated by the EPA. In a statement, Ford said C-Max and Fusion hybrid drivers reported a range of fuel economy figures, including some that surpassed 47 miles per gallon.
"This reinforces the fact that driving styles, driving conditions and other factors can cause mileage to vary," Ford spokesman Wes Sherwood said.
Consumer Reports said among current models, more than 80 percent of the vehicles it tested were within two miles per gallon of the estimates. The Fusion hybrid fell short by 8 miles per gallon, while the C-Max was off by 10 miles per gallon.
The Fusion hybrid still has the best fuel economy of any family sedan tested by Consumer Reports. The C-Max hybrid is second behind Toyota Motor Corp's (7203.T) Prius V.
"Make no mistake; both the Fusion Hybrid and C-Max Hybrid still deliver excellent fuel economy," Consumer Reports said. "But our tests show that buyers shouldn't expect the stellar 47 mpg that Ford is promoting."
The review comes a little more than a month after an EPA investigation showed that Hyundai Motor Co (005380.KS) and its affiliate, Kia Motors Corp (000270.KS), had overstated their fuel economy by at least a mile per gallon.
Last week, the Fusion won the coveted Green Car of the Year award at the Los Angeles Auto Show.
The Fusion, which competes in the bread-and-butter midsize sedan segment of the market, is a particularly important model for Ford. Earlier this year, Ford passed out T-shirts imprinted with the Fusion hybrid's fuel economy figures at an event in New York with Chief Executive Alan Mulally to promote the Fusion.
Also on Thursday, the EPA and the U.S. Department of Energy released their 2013 fuel economy guide, which includes sections on alternate-energy vehicles. The guide includes sections on electric vehicles, hybrids and plug-in hybrids.
The Fusion and C-Max hybrids are listed as getting 47 miles per gallon in the report. The models are the second-best in their class after the 2013 Toyota Prius and Prius c.
There are more than 40 hybrid cars, trucks and SUVs in the 2013 guide, which includes 14 electric vehicles, such as top-rated Toyota's 2013 Scion iQ EV, from 10 manufacturers. The Scion iQ EV gets the equivalent of 121 miles per gallon.
Three plug-in hybrid electric vehicles are rated. Ford's C-Max Energi tops the list with an EPA rating of 100 MPGe.
(Reporting By Deepa Seetharaman and Paul Lienert; Editing by Gerald E. McCormick, Sofina Mirza-Reid and Dan Grebler)