I doubt it would help, because as you suspected most of the heat is not the result of friction, but of resistance to current flowing in windings - called ohmic losses - and presumably also to magnetic losses. Even some of the mechanical (rather than electrical or magnetic) losses are due to windage rather than rolling or sliding friction.After reading the thread about the Tesla powered Cobra and stator temps being the limiting factor, I'm curious if DLC coating some of the parts in the motor could reduce the friction/heat generated by moving parts in the motor, thus reducing the stator temps.
IE could DLC bearings such as these substantively reduce stator temps, or is the heat in the stator not generated by friction?
This looks like a good description:
Where motor energy losses occur
This contains more detail about how heat is generated:
Keeping it cool: A look at causes of motor overheating