A vehicle’s ability to tow requires four things:
- Enough spare engine torque to pull the load without, for example, running out of steam on a hill
- Enough braking power to cope with the extra weight of the trailer
- The ability to fit a tow bar
- Enough chassis strength to cope with the pulling and pushing forces exerted on the tow bar
The majority of electric car manufacturers give tow ratings for their vehicles. Not all, though – the Nissan Leaf is not rated to tow, and it’s most likely due to the chassis strength.
One thing that electric vehicles have is instant torque. An internal combustion engine needs to rev to produce torque whereas electric motors produce the same amount of torque at any speed.
One of the big issues with towing a heavy load with a car with regular brakes is that brake fade can happen very quickly on a long descent. An ICE vehicle can use engine braking in low gears to help the foot-operated service brakes. In theory, an electric vehicle should be well-suited to the braking duties as the driver can use regenerative braking to supplement the brakes. Regenerative braking uses the resistance of the electric motors to recharge the battery. An issue with very heavy loads and very harsh braking is that the vehicle cannot deal with the power produced when braking, and it could overload the system.
Not all vehicles can accommodate a regular tow bar. A custom tow bar might need to be fabricated, which increases the cost significantly. The tow bar, which must be connected to the chassis, needs to have solid anchor points, and no risk of damaging the batteries, which are frequently located within the chassis.
Because the batteries form part of the chassis, and they are heavy, the chassis is not necessarily strong enough to accommodate the additional forces of a trailer.
How much can an EV tow?
With new EVs, the majority can tow between 500-750kg on an unbraked trailer. The most capable EV at the time of writing is the BMW iX 40 Sport. If we eventually get some serious utes such as Fords F150 Lightning Electric, then expect 3500kg to be the benchmark.
However, when towing the maximum capacity, expect to get less than 50% of the regular range of the EV, i.e. if your EV is usually good for 400km without a trailer, expect less than 200km with a fully laden trailer. Of course, this depends on how you drive the EV.
Where can you find out how to drive an EV most efficiently?
If you have purchased an EV and you are struggling with the range, then you need to get some training because EVs work differently to ICE vehicles. This EV training course teaches you everything you need to know to own and operate an EV, and reap the benefits of cheap fuel.