There isn’t a lot of data out there about how towing affects EV range, largely because there is such a diversity in trailer aerodynamics and mass. Thanks to the Oklahoma Chapter of the Electric Auto Association, we have some idea of how towing a 1.8 tonne car trailer affects the range of an Audi E-Tron.
The group of volunteers, supported by Audi of America’s electrification strategy team, drove the Audi while towing a trailer from Tulsa, Oklahoma to the Circuit of the Americas in Austin, Texas for an event hosted by the Fully Charged YouTube channel.
The team claimed an average efficiency of 1.3 miles (2.1 km) per kilowatt-hour while towing. The E-Tron has a 95 kWh battery, but only 84 of those are usable, which gives just under 110 miles (177 km/h) between full and empty batteries. EPA range for the SUV is 204 miles (328 km/h), so the trailer cut the available range almost in half.
This doesn’t sound great, but the added time wasn’t double. The team used 150kW fast chargers along the way that each took about 30 minutes to recharge 80% of the battery. They used the Electrify America and Francis Energy charging networks. They weren’t specific about which chargers were used or how long the trip took, but in an ideal case, this would have added a little over two hours to a journey that would normally take around eight.
I definitely wouldn’t get an EV if I were needing to tow a trailer 500 miles (805 km/h) more than a few times. But the occasional tow doesn’t add too much time, and upcoming electric trucks are claiming a lot more than 204 miles (328 km/h) of non-towing range. This wasn’t an exceptionally small or lightweight trailer. Also interesting was what was being towed inside the trailer: the first modern EV, a 1996 GM EV1.