iirc they can stall the front motor to create heat for preconditioning on the LR and P versions of the Model 3, how does the RWD one do it?
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How do RWD model 3 Precondition?
- Thread starter jackmott
- Start date
Slower? 
"Stall" is a weird way to put it but yes, when not in use the front motor can generate heat by spending ~3-3.5kW. I think it's the circuitry (converter?) that's used in that case, not the actual motor. Probably same for the rear but I'm not sure how easy it is to have that circuitry generate heat at the same time as driving the rear motor. It's possible that there's not much extra generated and "conditioning" simply means not cooling the motors but instead moving their heat to the battery? I know it does something, but I've heard plenty of people say it takes forever to condition in winter around here for RWD cars, it starts like 2h before arrival to the SC.
"Stall" is a weird way to put it but yes, when not in use the front motor can generate heat by spending ~3-3.5kW. I think it's the circuitry (converter?) that's used in that case, not the actual motor. Probably same for the rear but I'm not sure how easy it is to have that circuitry generate heat at the same time as driving the rear motor. It's possible that there's not much extra generated and "conditioning" simply means not cooling the motors but instead moving their heat to the battery? I know it does something, but I've heard plenty of people say it takes forever to condition in winter around here for RWD cars, it starts like 2h before arrival to the SC.
Slower?
Maybe all the RWD does is close the doors to the radiator and maybe do some trickery to heat up the rear motor.
"Stalling the motor" generates heat at 1 COP, but still has to be redirected into the battery using the coolant loop via octovalve. There's no difference between this for AWD and RWD except lower total heat flow with just 1 RWD motor.
In normal outdoor temps, I believe the car uses the heat pump to transfer heat into the coolant loop for heating the battery. This is more efficient and has a higher COP. In very cold temps <-10C, the car can use both the compressor and drive unit for generating heat - see
The entire video series is good info on how thermal management is performed via the octovalve.
In normal outdoor temps, I believe the car uses the heat pump to transfer heat into the coolant loop for heating the battery. This is more efficient and has a higher COP. In very cold temps <-10C, the car can use both the compressor and drive unit for generating heat - see
The entire video series is good info on how thermal management is performed via the octovalve.
AlanSubie4Life
Efficiency Obsessed Member
Just a note that this doesn’t exactly apply to older RWD/AWD (no heat pump), which use the Superbottle. But the motor can be used to generate heat just the same. It can walk and chew gum.
In regards to using the rear motor for heat while driving...it doesn't do it very well. After going above about 30mph, the non-locomotive heat generating energy drops down to negligible values. It has a hard time "walking and chewing gum at the same time". Now with the newer heat pump vehicles it has other sources to pull heat from to push around.
That's what I thought as well, that doing both wasn't possible or practical. I don't know exactly how they do it but since they use the same DC->AC conversion circuitry and it's occupied generating the current to drive the motor forward, there's a physical limit to what else it can do without causing trouble to the driving. Thanks for confirming.
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