Plugging in helps, although it doesn't come free
How efficient is the C-Max Energi? I topped off our test vehicle carefully (difficult given its capless system) before my week of driving. We then drove 440.1 miles, of which the trip computer said 163.3 miles were in EV mode (that includes true plug-in miles plus mileage in hybrid mode when the gasoline engine is off). At the end of that period, it summed that I'd used 10.23 gallons of gas and 15.8 kWh of electricity from plugging in. In all, that adds up to 41.1 MPGe, it said.
That includes about 360 miles of highway driving (nearly all in hybrid mode) as well as about 80 miles around town (nearly from plug-in battery power).Here's where it gets especially confusing: In the C-Max Energi's set of highly configurable and customizable screens, it displays its overall efficiency based on MPGe (in terms of miles per the energy content in a gallon of gasoline). And in general, those numbers soar (misleadingly high, it seems) whenever the electric motor system is on then plunge when the gasoline engine fires up.
Using that 10.23 gallons (or the 10.27 gallons we recorded on a careful refill), our consumption figures out to a real, non-equivalent 43 miles per gallon—when you don't figure in the energy from plugging in. So plugging in several times (at the expense of about $2 of electricity, tops) probably netted us about five more miles per gallon, if you go by the 36-38 mpg that we've seen in the C-Max Hybrid over some other comparable real-world drives.
Since I estimated that I'd used the capacity of the battery pack about three full times through, that emphasizes a point that—for longevity, perhaps—the system isn't quite using the full capacity of the 7.6-kWh battery.
In any case, Ford says that C-Max buyers are plugging in more often—and using their all-electric mode more often than anticipated. They'll certainly save money, too, by plugging in, but it's nothing that will make the Energi's $33,745 base price feel like a bargain.
Better than Prius, but numbers not as favorable
Altogether, it's really tough to find fault in anything about how the 2013 Ford C-Max drives—especially if, as we did, you use the Toyota Prius as a benchmark.
Is the Ford C-Max Energi a lot more fun to drive than the Prius or Prius V? Absolutely. Compared to the Prius, which tends to highly discourage you from moving along briskly, the C-Max almost invites it, with its responsive driving character.
At the same time, that may be part of Ford's problem in not seeing real-world mileage that's quite as high as claimed—at least not yet. As we see more owners understanding the complex set of displays and how their cars work, we think many more buyers will be happy with what the Energi models do. Maybe not entirely happy with the money or fuel they've saved, but happy with the vehicle.