On Swiss roads, more and more trailers are on the move. Over the past ten years, their number has increased by 18 percent. As the number of electric cars continues to grow, the TCS examined whether electric cars are also suitable as towing vehicles. The focus was particularly on towing capacity and the impact on range. For the study, five electric cars from manufacturers BMW, Audi, Tesla, Volvo, and Maxus were used, each with a towing capacity between 1600 and 3500 kilos. The test ensured the towing capacity was as close to the maximum as possible. To conduct the test, all five vehicles with trailers drove the route from the TCS Test Lab in Ittigen (BE) to Villeneuve (VD) on Lake Geneva. The topographically demanding route was 198 kilometers round trip and mainly led over the motorway.
With a trailer, consumption is twice as high
The study revealed that the additional consumption (kWh/100 km) when towing a trailer averages 103.4 percent, more than twice as much as when driving without a trailer. The biggest discrepancy was with the Tesla Model Y, whose consumption with a trailer was 147 percent higher than without. This is because this electric car has remarkably low consumption without a trailer. The different models are hardly comparable to each other, as the towing capacity was not the same everywhere. Naturally, the trailer also affects the range of the cars. On average, they lose about half of their range when towing a trailer that is near the maximum load.
For combustion engines, the TCS has no comparable study, but a reference measurement was taken with a VW Caddy from the TCS Patrol. With a trailer, the diesel consumption was 74.5 percent higher, and the range of the tank fill reduced by 43 percent. Note that the VW Caddy had a high unladen weight due to the patrol equipment, so the values are not representative for other similar diesel vehicles.
Electric cars have an advantage on inclines
The study showed that there are definitely electric cars that can serve as towing vehicles - particularly when they have a towing capacity of 3.5 tons, matching the combustion engines. The loss of range due to towing a trailer is similar to that of combustion vehicles. An advantage of electric cars is the high torque of the electric motor, which significantly improves towing power on inclines. However, a challenge is the diminishing range during towing. While many charging stations are available along motorways and main roads, they often need to be driven forward or backward, which can be extremely cumbersome with a trailer depending on the surroundings. The 'eTrucker' app is helpful here, identifying charging stations for e-trucks that can be used without unhitching the trailer.