We are sent questions frequently here at AutoTrader as part of our Ask AutoTrader service. Many of these come up often enough that it warrants writing an article about, and the following topic happens to be one of those instances. How does driving an electric vehicle (EV) in extreme weather conditions like high temperatures or heavy rain affect performance? We used a USA-based test carried out by the AAA as our source.
Related: How do I track and monitor my electric car's energy usage and efficiency?
Rain
While rain negatively affects an EV's range, it has less to do with how the moisture affects the battery or motor. It is more about how the added water on the road surface marginally increases rolling resistance. However, this is true with all vehicles and is not exclusive to EVs.
Temperature
Temperature is a key consideration for electric vehicles, and the study came to some interesting conclusions. It is important to note that internal combustion-powered cars are also negatively affected by extreme weather temperatures, but from what we can find, it's less apparent than with EVs.
Cold- Looking at the data, an ambient temperature of -6.5°C resulted in a 12% decrease in combined driving range and an 8% decrease in combined equivalent fuel economy compared to testing conducted at 24°C. Using the vehicle's air-conditioning system during these low temperatures resulted in a 41% decrease in combined driving range and a 39% decrease in combined equivalent fuel economy compared to testing conducted at 24°C.
Heat- Heat has been shown to negatively affect the range of an EV, with the aforementioned study finding that at operating temperatures of 35 degrees Celsius, there was a 4% decrease in combined driving range and a 5% decrease in combined equivalent fuel economy. When it's hot outside, we tend to make use of airconditioning, and this again spells bad news for an EV's range, with the study concluding that there is a 17% decrease in both combined driving range and combined equivalent fuel economy (when compared to testing conducted at 24°C).
