2014 BMW i3 REx range-extended electric car owned by Tom Moloughney - in dealership showroomEnlarge Photo
When you slow down to less than 15 mph, the REx shuts off unless battery charge is very low (I would guess less than 3 percent of usable capacity), but you'll have to drive it hard to get the battery that low, because the REx provides enough energy to let the battery hold the minimum charge level well. I tried to overwhelm it with high-speed driving, although I wasn't able to because of the rain and traffic.
All in all, I drove 115 miles (69 miles in all-electric mode, plus 46 miles more with the REx running). The car performed flawlessly, and other than the slight hum you can hear inside when the range extender operates at its high speed, you wouldn't even know the i3 wasn't running all electric.
I'll be testing my new car a lot more, but as far as I'm concerned, this should lessen worries and talk about any kind of "limp mode" from an overwhelmed range extender.
I'm personally convinced the car can do anything in extended-range mode that I need it to do, without compromise. I think customers are going to love the feature, especially in the U.S. where we drive longer distances. That said, I am sure I will be able to overwhelm the REx if I set out to do so--and I plan to do just that in testing soon.
2014 BMW i3 REx range-extended electric car owned by Tom Moloughney - famous EFOPEC license platesEnlarge Photo
Also, the route I was on had hills and downgrades, but it certainly wasn't severe mountain driving, which may have an effect on what the REx can and can't do. Clearly the range extender will have some limits, but for how I'll use the car, I'm certain it can do what I want without problems--including regular 230-mile journeys to my in-laws in Vermont.
Other than having to stop to fill the 1.9-gallon gas tank three or four times on longer trips like those, I'm sure the i3 will be fine, even if the final portion of that trip is mostly uphill. Filling the tank will likely take me all of three minutes, so once-an-hour stops aren't likely to bother me much.
If I were doing those kinds of trips every day, though, I would likely choose a different plug-in hybrid or range-extended vehicle--a Chevy Volt, for instance--but for long trips that happen every month or two, this will work just fine.
Take a good look at the pictures, because in the next photos you'll see, the car will look totally different: Today, I'm taking it for a full body wrap. That shop is more than 130 miles away, so once again, I'll get to test out the REx.
Stay tuned for my next update, and please post any information you'd like to see in my next installment.