Geotab published new research showing that driving speed affects electric vehicle range far more than air conditioning during summer months.
The telematics company analyzed data from over three million trips to understand how temperature and speed impact energy consumption in light-duty EVs. Their findings challenge common assumptions about what drains EV batteries fastest in hot weather.
Speed matters more than climate control.
At highway speeds between 50-80mph in temperatures above 30°C, aerodynamic drag consumed significantly more energy than cabin cooling systems. The effect becomes more pronounced as speeds increase.
A 65kWh electric van demonstrates the dramatic impact. Cruising at 50mph in 30°C heat with air conditioning running provides roughly 143 miles of range.
Increase that speed to 60mph and range drops to 121 miles. Push it to 70mph and you’re down to 103 miles. At 80mph, range falls to just 88 miles – that’s a 39% reduction across a 30mph speed increase.
Electric saloons perform better due to superior aerodynamics, but they still face significant range penalties at higher speeds.
The physics behind the numbers are straightforward.
Air resistance increases exponentially with speed. Doubling your speed requires four times the energy to overcome wind resistance – far exceeding what any air conditioning system demands.
“Drivers tend to worry about using the aircon in hot weather, but our data shows that your right foot can make the biggest difference, particularly at high speeds,” explained Charlotte Argue, senior sustainability manager at Geotab.
At 50mph, some electric saloons achieve 277 miles of range with air conditioning running. Increase to 60mph in identical conditions and range drops to 251 miles. At 70mph it falls to 226 miles, while 80mph reduces range to 200 miles – a 28% decrease over the same 30mph bracket.
Temperature effects vary with speed.
Warmer air temperature has more noticeable impact at lower speeds, where air conditioning draw becomes more significant relative to minimal air resistance. As speeds increase, temperature becomes less important compared to the energy required to maintain velocity.
The research used anonymized telematics data comparing energy use across family saloons and cargo vans in real-world conditions.
“Just slowing down by 10 or 15 mph can extend your range by 20 to 30%, depending on the vehicle,” Argue noted. “Modern EVs have increasingly large batteries, and many can comfortably handle most daily driving – including fleet routes – on a single charge.”
Range will always vary with real-world conditions including temperature, topography, traffic and speed. But understanding which factors have the greatest impact helps drivers maximize their EV’s capabilities during summer months.
