AAA has published a study that confirms what motorists who drove an electric vehicle through the polar vortex likely already know: Freezing temperatures reduce an EV's driving range. Additionally, an electric vehicle with a compromised driving range will require charging more often, which increases the cost to operate the vehicle.
The study looked at five electric vehicles popular in the United States - 2018 models of the BMW i3s, Chevrolet Bolt, Nissan Leaf, and the 2017 models of the Tesla Model S 75D and Volkwagen e-Golf.
"The research clearly shows that electric vehicles thrive in more moderate climates, except the reality is most Americans live in an area where temperature fluctuates", Megan McKernan, manager of Automotive Research Center, said in a statement.
Many owners discovered the range limitations last week when much of the country was in the grips of a polar vortex.
Real-world driving conditions were simulated using a dynamometer, essentially a treadmill for cars, in a closed testing cell where ambient temperature could be closely controlled.
The AAA study reveals that when the mercury dips to 20°F (about minus 7ºC) and the HVAC system is used to heat the inside of the vehicle, the average driving range is decreased by 41 percent.
AAA found range also declined when the air conditioner was on in 95-degree weather.
For example, AAA's testers determined that the Tesla's range when fully charged at 75 degrees was 239 miles, but it fell 91 miles, or 38 percent, at 20 degrees.
In a statement, Tesla disputed the AAA results. Drivers should also try to limit HVAC use to minimize the impact on driving range, and understand that during periods of cold weather, using heat may significantly increase energy costs. Range would take a hit mainly for short trips, and the decrease wouldn't be as large on longer trips once the battery and cabin are heated, Hughes said. "If you want to go somewhere far in the cold, you're going to be using more power".
Cold weather reduces EV range by almost 50%.
Plan ahead. When drivers are aware of the weather conditions before heading out, they can plan for more frequent stops for charging as well as identify the location of charging stations.
AAA advises electric vehicle owners who live in areas with extreme weather to plan ahead, especially during the winter months.