Icy Road Accident Possibly Caused By Regen

[DFibRL8R]

+1 for winter tires.

It is a heavy car. I never used winter tires until I went through 2 winters on all seasons in my RWD Model S (yes I am a slow learner). I experienced various unpleasant driving situations with traction loss on icy surfaces (even just driving in a straight line at modest speeds and the car could start to slide a bit). As a result, I now keep an extra set of winter tires/rims which I swap in from Mid November to Mid March. They also provide better stopping in cold dry pavement conditions than all seasons. I've had no problems since.

 

[animorph]

The Porsche 911, with a heavy rear weight bias, was well known for "trailing throttle oversteer", which is just losing traction at the rear due to lifting the gas pedal too abruptly. Certainly a problem on ice, but also in the middle of a corner if you're at the limit. The solution is to only release the throttle up to the point where the car would maintain a constant velocity, or a little farther if conditions allow. That is not all the way off the throttle. You have to keep the engine spinning and make up for drivetrain losses or else you are slowing down and making the tires work a bit harder.

In a Tesla that means finding the acceleration/regen boundary on the go pedal when the car is losing traction, and then carefully using more regen as conditions/traction control allow.

Driven manually at higher RPM's ICE cars can have as much engine braking as a Tesla has regen braking. In fact, I had my 924 Porsche out on a track once when my brakes faded badly (change your brake fluid!). I did the last few laps using pretty close to engine braking only, but without losing too much time. Tesla's regen is far from unique with respect to car dynamics.