Have an option to only use regen when Autopilot needs to brake, if safe to do so.
When you’re on autopilot or adaptive cruise control, and your car needs to come to a stop (either because there’s a slowing or stopped vehicle in front of you or it’s automatically stopping for a stoplight/sign), I notice that the car appears to use the brake calipers in addition to regen braking (above 5 mph).
To increase the lifespan of the friction brakes, I prefer to only use regen unless the other vehicle is stopping harder than expected. Many times I’ll disconnect AP so I can manually use regen – meaning I’m starting the deceleration process sooner than Tesla would. I understand in my older Model S, it only regens down to about 5 mph so brakes would be required for a complete stop.
Implemented in vehicles with permanent magnet motors. For induction motors, there is no regen available at very low speeds, hence the need for friction brakes. Also, brakes used at these slow speeds cause negligible wear on the brakes.
Definitely not a stupid question. I compare the rate of deceleration when I manually allow the car to come to almost a stop, without using the brake pedal, compared to how quickly it decelerates when it's stopping on autopilot. The difference would be due to the addition of calipers in helping it slow, since there isn't a greater regen force that's applied.