Zero maintenance. Wound copper magnet, instead of rare earth magnets. Above 95% efficient.
Whenever these become mainstream I'll be interested in comparing them to the Elaphe motors Aptera is currently using.
Slightly closer to reality than a university breakthrough, but we'll see...
Again the magnetic field created is proportional to current and number of turns voltage does not come into the equation. ( You actually want to keep the voltage as low as you can, but there is a optimum balance) You control the speed of the motor by the frequency sent to the motor, the strength of the electro magnetic magnetic field is controlled by the duty cycle of this frequency, therefore there is no need to control the magnetic field of the magnets.
It is very hard to create magnetic fields as strong as rare earth magnets with electro magnets. Not counting the I square R losses in the electro magnet.