A study by AAA backs up our own observations that electric vehicle performance is adversely affected by temperature.
A study published this month by AAA provides hard to dispute evidence that electric car owners need to plan on significantly reduced range when driving in cold weather conditions. The study found that winter temperatures dramatically impact both the range and energy usage of electric vehicles. The batteries are affected by the temperatures alone, but the real range-killer is the heating you need to occupy these green machines comfortably.
This is not news to anyone who has tested electric vehicles. In our own testing, we have found that is pretty much impossible to match the optimistic range miles displayed when starting out on a trip with the actual miles one covers. For example, in one recent winter test of a luxury electric vehicle, we began our journey at an odometer reading of 1,820 miles and concluded the journey 14 miles later at 1,834. However, the range displayed at the start of our trip was 142 miles, and at the end of the trip, our remaining range displayed was 116 miles. So we covered 14 miles but consumed 26 miles of range. This is not unusual. In a separate test of an affordable electric vehicle, BestRide used 49 miles of range to cover just 29 actual miles. We should stress that these tests were in normal driving and that we almost never test any gasoline-powered test vehicle that has lower mileage than its EPA Combined estimate. When we do, we are always careful to point it out.
AAA’s study included two premium models, a 2017 Tesla Model S 75D and a 2018 BMW i3, as well as three affordable battery-electric cars, the 2018 Nissan Leaf, 2018, eGolf from VW, and the 2018 Chevy Bolt. Without exception, each vehicle showed a significant drop in range and efficiency when tested at 20F versus 75F, and none of the vehicles came anywhere close to their maximum advertised range in winter conditions. The average range reduction due just to lower temperatures was 12%. However, if one uses the vehicle’s heating system the range dropped by an average of 41%. Testing at 95F resulted in an average decrease of 17 percent of driving range compared to 75F.
AAA looked closely at the cost associated with EV use in hot and cold temperatures and concluded, “Depending on ambient temperature, HVAC use results in a significant monetary cost increase.” Despite EV advocates’ claims, using an electric vehicle is far from “free.” Using one of our own homes as an example, we found that electricity usage increases by as much as 56% when a high-efficiency EV is added to a household. As the EPA chart shows above, gasoline-powered green vehicles offer similar costs per mile for energy as battery-electric vehicles operated under ideal conditions.
Among all of the five vehicles tested, the Nissan Leaf performed the best and had the lowest percent change in range due to cold weather and HVAC usage at about 32%. The BMW i3 performed the worst, with a range reduction of over 50%.
The talk among vehicle testers has been that electric vehicles, unlike gasoline-powered green vehicles, do not live up to their promised EPA range or efficiency in real-world use. AAA’s study now gives us hard evidence supporting that opinion.