By David Thomas on April 22, 2011
There is one thing today that separates an electric car from a gasoline car. Its power comes from a battery, and that battery needs to be recharged.
This fundamental shift in how car owners think about refueling their vehicles is why Cars.com purchased a 2011 Chevy Volt in January and a 2011 Nissan Leaf a month later.
We drove these cars in temperatures ranging from minus 2 to 67 degrees in the Volt and 24 to 82 degrees in the Leaf, and both lived up to their billing. But after recording driving data from each outing with both vehicles, we discovered two significant issues an owner will face: how cold weather affects them, and how much you’ll need to rely on a somewhat erratic car computer telling you how far you can drive.
Chevy says the Volt’s range on battery alone — it also features a gasoline engine that works as a generator to power the electric motor when the battery is emptied — is between 25 and 50 miles.
When we picked it up from the dealer in sunny California on Jan. 3, its range was 33 miles. We didn’t see that number again in Chicago until March.
The lowest predicted range on a full charge we saw was 24 miles when it was 36 degrees out, but the Volt traveled 28.8 miles that day. It took 20-degree temps to bring the actual-miles-driven number lower.
On four different occasions of temperatures registering 25, 27, 25 and 26 degrees on the car’s computer, the Volt traveled 23.8, 26, 23.3 and 21.3 miles, respectively. All of these ranges were lower than the prediction, but three were within 10%, and one was within 20%-- tighter than the variances we witnessed with the Leaf.
Both cars allow owners to turn on the heat or air conditioning while still plugged in to get the cabin to an optimum temperature before being unplugged, so the overall range won’t be diminished by the energy-sucking environmental systems. In one of the examples above, when we achieved 26 miles, the car had been pre-conditioned, and that led to the most accurate prediction.
What about the minus 2 day? The range was listed at 32 when I unplugged the pre-conditioned Volt from my garage outlet. It dipped to 31 before it left the driveway and ended up traveling 20.9 miles on battery power.
When the weather was in the mid-30s, the predicted and actual ranges averaged around 30 miles, with smaller errors than we saw when it was less than 30 degrees.
We reached ranges of 34.5 and 33.6 miles — our best — when it was 56 and 67 degrees, respectively, near optimum weather for driving any vehicle. However, the starting range had been 38 and 30 miles, respectively. That’s nearly a 10% swing.
The difference in predicted and observed range isn’t going to stop a Volt owner, but if you drive an all-electric Leaf, you have but one powertrain to rely on and the range means everything. However, in our testing, the Leaf didn’t turn out to be as predictable as the Volt, and out of the two, it needs to be.
This spring we’ll be able to observe how both cars make the transition to a pleasant spring — we can hope — and into a hot, humid summer that requires air conditioning. Will these two cars go through a similar reversal in range? Stay tuned.
Managing Editor David Thomas has a thing for wagons and owns a 2010 Subaru Outback and a 2005 Volkswagen Passat wagon. Email David