Flat-towing an electrical vehicle—that’s, towing it with its wheels in touch with the road—is harder than with internal-combustion vehicles. But automakers are working on solutions.
When internal-combustion vehicles are flat-towed, their transmissions are shifted into neutral, or prop shafts are removed or disengaged, to permit the normally-driven wheels to rotate freely without risking damage to mechanical components. But mechanically decoupling electric motors from the wheels they normally drive is not as straightforward with EVs.
Stellantis EV flat towing patent image
In a patent filing published by america Patent and Trademark Office (USPTO) Jan. 30, 2025 (and submitted Jul. 24, 2023), Stellantis proposes another, for vehicles equipped with permanent-magnet synchronous motors, not less than. A high-voltage bus may very well be used to induce field weakening, reducing the torque of the motors and allowing them to spin more freely, while being isolated from the battery pack.
It is a somewhat simpler solution than the one proposed by Rivian in a patent filing that surfaced just a couple of yr ago. In that filing, the automaker discusses using software to disconnect the motor or motors that may normally power the rear axle, while still applying torque to the front wheels to maintain the vehicle from rolling out of sync with the tow vehicle.
Rivian free-wheel towing patent image
In earlier patent application, published by the USPTO in 2021, Ford takes things a step further by suggesting that EVs could selectively be charged when towed. That also opens up the opportunity of using the EV to assist boost the tow vehicle up hills, just like what startups Pebble and Lightship have built into travel trailers.
While flat-towing may not be a primary concern for all EV shoppers, it’s popular with RV owners, and will also make it easier to get better stranded EVs, reducing the need for flatbed trucks. So these patented ideas could prove quite useful in the event that they’re ever applied to production vehicles.
This Article First Appeared At www.greencarreports.com
