Can I Buy an EV which Can be Flat Towed?
This question is one of many that has started to be heard more frequently, and it will become more important as increasing numbers of us choose an electric vehicle as our day to day driving vehicle. The short answer is NO!
There are numerous reasons for this:
1) At the present time, as this TT is being written (in January, 2024) there are NO EV manufacturers that have specified that their electric vehicle is flat towable.
2) All EVs are direct drive, the electric motor is directly connected to the driven wheels with rarely any method of disconnecting the drive axle from the motor. Thus, rolling the car in ‘Neutral’ rotates the driven shaft in the motor. Since motors are not designed to be utilized in this way, damage can (and likely will) occur.
3) It is likely that any heat, potentially generated when towing, could damage the remainder of the motor, if the EV motor cooling system is not functioning.
While I have not been able to confirm this statement, there have been rumors that Tesla may consider modifying the control software to allow limited flat towing, even potentially using the energy generated while flat towing to recharge the main battery of the Tesla through regenerative braking. Obviously, this feature could only operate if the EV battery is low on charge (so that it could accept the charging power) and would have to cease automatically once the EV battery is fully charged. The low voltage (control system) battery would need to be close to fully charged to allow all the required internal car systems to monitor and operate the charging and cooling of the EV battery. The controls for this would be software based and require a driver/user to set the RV towing mode, prior to towing and then return the vehicle to driving mode, when RV towing is done. This operation, while different is not unique to towing an EV. Most Internal Combustion Engine (ICE) vehicles require setting up the vehicle to tow and doing something to return them to the driving mode, to be able to be driven.
Assuming that the above hurdles could be overcome then we also have the issue of connecting the towing platform or towbar mounting and wiring to the EV safely. As much as I’d like to suggest that this is something a RV or towing specialist shop could handle, we are dealing with vehicles that have a significantly different front-end assembly (since there is no engine compartment) and the ‘frame’ assemblies are much different from ICE vehicles. Most EVs do not have a conventional grille and little or no underhood access to the front area under the hood. It is conceivable that the maker could produce a modification to the car’s structure to facilitate the attachment of a towing assembly and tow bar tabs. The challenge would be how to bring the attachment points up to a position that would allow the towbar to be level with the RV hitch receiver, while not being unsightly.
Lighting and Braking Control:
Then, there is the question of how to connect RV’s tow vehicle wiring to the EV. The newest EV’s are beginning to use a 48-Volt ‘low voltage’ battery architecture for all lighting and control systems, having eliminated the conventional 12-Volt battery system, thereby greatly reducing the wiring that most ICE vehicles use. There would need to be a way of interfacing with the EV’s systems to allow its brake, signal, and taillights to operate from the EV’s power system and yet be controlled by the RV’s respective systems for those functions. Braking could be controlled by the RV which could potentially utilize the EV’s regenerative braking system. Another factor that enters the picture is, if the EV’s systems are operating, then there would be the requirement to turn off, while being towed, any warning systems active when a vehicle ahead is too close to the EV. Without doing this, it is probable that the EV will alarm and re-act to the fact that a vehicle (the RV) is too close when braking, among other situations. Otherwise, the EV could activate the preprogrammed collision avoidance mode, which would be active when the EV’s control system is operating, to allow computer control of the various vehicle systems in the flat tow mode. This would be part of the software modifications necessitated by the towing and would be implemented by the putting the EV in Tow Mode, which would disable this and similar warnings and functions.
Alternatively, the RV owner could choose to install a pair
of LED magnetic lights. The challenge with using these is that many EVs use
composite or aluminum panels, thus the magnetic attachments would not work. The
solution which eliminates any connection to the EV’s lighting system is to
install a LED Light Strip which has all the functions in that strip. I chose
this option when I dolly towed my Kia Niro EV on a tow dolly. The strip is
usually used on the rear of a pickup truck, attaching on the bottom of the box bed,
just below the tailgate. The one we chose provided amber directional turn
signals, red running lights and brighter red brake lights. Of course, this choice
will mean the strip must be mounted on the EV body (rear bumper surface) as
shown on the
photo. The advantage this approach provides is that the RV power connection which at the present time is 12 volts, will directly control the tow vehicle lighting, brake lighting and signals, with no connection to the EV. I would highly recommend the installation of a coiled light cable between the RV and the EV to ensure a solid electrical connection between the two vehicles.
In the interim, as we wait for these improvements to become a reality, the alternatives may be to forgo flat towing, use Uber or a rental at your destinations or to tow the EV on trailer. The Dolly towing method in TT#137 may be a reasonable alternative in the immediate future, as long as you choose a Front Wheel Drive (FWD) EV, until the industry makes some more options available.