That's not going to produce a 20x gain in efficiency. The primary problem with electric cars is energy density in the battery itself.

Maybe if mag-lev cars are possible, you could get that kind of gain from the reduced friction.

If your loss goes from 5% to 1%, you have to deal with 80% less heat. So you can make 3x smaller motors. All the powertrain of these machines will be hugely simplified.

That's no small deal, but in the grand scheme of things that a hot superconductor can give us.. I mean, this can (possibly, with decades of research) give us fusion, quantum computing, etc.

Are most of the losses in the motor? I figure it'd be friction in the drive train, the bearings, air drag, etc.

The motors are not a constraint though for electrical vehicles. The motors are already much smaller than equivalent ICEs, as seen in the empty "frunks" in most electric cars.

Agreed Fusion would be the biggest win possible.