I think we can all agree that driving style and road conditions have a significant impact on how fuel efficient a vehicle actually is.
Meaning, just because a window sticker claims a vehicle is rated at 47 mpg doesn't mean you will see that sort of efficiency in real world conditions. As you may recall, automaker Hyundai recently landed in hot water over inflated fuel efficiency claims and was forced to revise its official window stickers.
And now Consumer Reports is hinting that Ford may be over-estimating fuel efficiency claims. Indeed, the auto manufacturer says both its C-Max Hybrid and the Ford Fusion Hybrid offers drivers fuel efficiency of 47 mpg in the city and on highway. However, CR notes that owners of these hybrid vehicles are claiming the fuel economy doesn't live up to Ford's promise.
To be sure, the EPA website has estimates from 14 real world C-Max Hybrid owners and five 2013 Fusion Hybrid owners. According to these statistics, the C-Max Hybrid averages 40.5 mpg while the Fusion averages 37.1 mpg. Clearly, we have to take those numbers with a grain of salt because there is no indication of the driving style or the environment where these fuel efficiency numbers were gathered.
However, Consumer Reports has purchased its own C-Max Hybrid and Fusion Hybrid and confirmed via road tests that the vehicles don't quite live up to Ford's 47 mpg claim, with the onboard computer system in the C-Max showing fuel efficiency between 33 mpg and 39 mpg. Consumer Reports also note that it tested the Fusion Hybrid for a couple of weeks, all while recording efficiency of approximately 40 mpg during a long highway commute.