Ford plug-in hybrid drivers are really making the most of the electric range of their vehicles--with nearly 60 percent of trips done entirely gas-free.

That's according to Ford itself, using aggregated data from the MyFord Mobile app.

The most interesting thing is that as many Ford plug-in owners are driving gas-free as their Chevy Volt counterparts, despite the shorter electric range.

One year ago, we reported how 63 percent of Volt miles are electric--suggesting drivers really were making the most of their Volts and plugging in wherever they could. At the same time, the remaining 37 percent of trips seemed justification enough that the Volt's drivetrain works, and allows people to drive that little bit further when required.

Ford's Fusion and C-Max Energi plug-in hybrids may only have a 21-mile electric range, but that's evidently enough to cover the bulk of their driving despite it being little more than a half of the Volt's 38-mile electric range.

20-50 miles perfect for plug-ins?

It raises an interesting question: Just how many miles does your plug-in need to go in EV mode alone?

The question hinges on just how far the average American commutes, and how frequent their longer journeys are.

Using the Ford's 21 miles as a baseline, you can see why. Just under 60 percent of Ford plug-in miles are all-electric, yet only a few percent more, with almost double the range, are all-electric in the Volt. Ford's own figures show that 84 percent of its drivers' trips are under 20 miles.

Figures for the Prius Plug-In, with its 6 continuous miles or 11 blended electric miles, are hard to come by--but it isn't hard to imagine that a significantly lower proportion of journeys are completed all-electric in that car.

Naturally, if you add enough electric miles to a range-extended or plug-in hybrid car, you'd start to see drivers completing significantly more than 60 percent of their journeys electrically. So think of it as a graph: Low electric percentage below around 15 miles, then a climb and a plateau between 20-50 miles of electric range, evidently enough to cover between a half and two thirds of most drivers' journeys.

Add more miles, and the graph starts climbing again--to the point where a plug-in or full battery electric vehicle with a long enough range can cover 90-plus percent of the average driver's trips.

Confidence builds

There's more to Ford's plug-in results than range, however.

One thing the company is noticed is that as drivers get used to their cars, they push the electric range further. This is something common to all electric vehicles, as drivers gain the confidence to do longer trips on however many electric miles they have.

It's a figure Ford has seen rise as drivers get used to their cars. Initially, Ford plug-in drivers were completing only around 40 percent of their journeys all-electric.

With a plug-in hybrid there's no range anxiety of course, but it seems that Ford plug-in hybrid drivers, like their Volt counterparts, really do want to make the most of their electric range, rather than letting it run into gasoline mode.

How far do you go?

So, all of this in mind, what do you think?

Is the 20-or-so miles of electric range in the Ford Fusion and C-Max Energi a sweet spot for electric range, high enough for most trips and low enough to reduce the need for bigger, more expensive battery packs?

Or could it be as simple as Ford's plug-in drivers simply driving fewer miles--and therefore completing a greater number of those miles with their shorter electric range?

Let us know how you do with your own plug-in hybrids and range-extended cars below.

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