Rivian R1S
Sitting next to an SUV with that model designation. Nice looking rig, appears to be in the same chassis as pickup. No plates out. Marty
Forum Discussion
JRscooby wrote:time2roll wrote:
After a bit more reading... Rivian seems to no longer endorse four-down towing of the vehicles. :(
Bollinger had made the same comments and then shifted out of the personal market to focus on commercial.
There are no EVs that can be towed on all four wheels that I am aware of.
Can anybody tell what the issue is that would prevent flat towing? For years, ICE cars was the transmission did not lube itself unless the input shaft was spinning. Which implied spin the engine. EVs don't have transmission, so that's no problem. No disconnect between wheel and motor? Well spinning the motor, with no power to it, does no harm, as long does not exceed speed it would normally run. (Going to tow faster than you would drive?) Steering and brakes would be no more complicated than ICE.
Most EVs have an electric clutch (or connect/ disconect) between the wheels and the transmission. They don't have many components but they have a single or in some cases a 2 speed transmission (very simple, nothing like what am ICE has)
Due to the high torque of the electric motors, the traction control systems are much more complex than ICE's and monitor wheel speeds with a much higher frequency and precision.
The same problem happens with the regenerative breaking in snowy/icy condition. It is very easy to loose traction on ice and as it is involuntary (meaning the driver does not press the brake or anything else, it is activated automatically) so the system is monitoring not only the wheel speed independently several thousand times per second, it also triangulates with GPS and accelerometers to ensure the wheels are always "in traction".
All of this said, the problem is that flat towing something that complex may create unforseen problems, so lawyers said "How many more sales are you going to get by allowing flat towing? Is it really worth the risk?" And the answer was always "No".
There is no inherent technical reason (like the transmission in an ICE), it is simply "Why risk it, we are selling every unit before its built..."
I have towed one of my leafs and one of my BMW but just to see how fast did they charge, and o boy did they complained!
