Michigan Radio tests fuel economy of C-Max; your mileage will vary

Feb 28, 2013

Credit user: Matthias93 / Wikimedia Commons

I recently conducted my own, informal test of the fuel economy of the Ford hybrid crossover, the C-Max.  I was curious to see what number I could achieve, in light of the ongoing controversy.

Consumer Reports and now two lawsuits claim Ford's advertised number of 47 mpg is unreachable.

So, on a 30-degree evening, not too windy, no snow in the forecast, I set out from Ann Arbor, reset the fuel economy calculator, set the cruise control at 55 miles per hour, and drove.

By the time I got to my destination (the border between Detroit and Windsor), the computer said I'd gotten just over 46 miles per gallon. 

However, driving 55 can sometimes be an exercise in willpower, as cars exceeding 75 mph whiz past. You've got to hope they're paying attention and don't run into you.

On the drive home, I set the cruise control at 70. That's closer to the speed I normally drive when I'm on the highway. And my fuel economy – no great surprise – was much lower. By the time I reached Ann Arbor, my fuel economy for the return part of the trip was just over 36 miles per gallon. A big difference.

Now, Consumer Reports tests cars going a steady 65 miles per hour on the highway. 

The way the EPA number is derived is very different.

Auto companies put their new cars through a standard test, in a lab, that attempts to approximate a variety of driving conditions, at a variety of speeds, but nothing over 65 miles per hour.

Ford Motor Company says hybrids in particular are highly sensitive to the way someone drives and the conditions under which the car is driven.

I'd say that's true for just about any car.

My husband can get 45 miles per gallon on long trips to Waubaushene, Ontario in our 2011 manual Ford Focus, beating the EPA 35 mpg sticker by 10.  (He's the guy going 58 miles per hour in the right-hand lane). 

On the highway, I get no better than 37 miles per gallon in that same car, driving my usual 70 miles per hour. Still, that's two miles per gallon better than the EPA sticker. 

Do car companies need to include a disclaimer at the end of their ads?  Maybe a voiceover, really fast, "your mileage may differ from the EPA number. By a lot." 

And maybe we all need to be reminded, if we slow down, we will get better gas mileage.