Those require expensive rare-earth permanent magnets, and BLDC require expensive inverter controllers. Plus, even though the best BLDC are maybe 93% (after inv

Those require expensive rare-earth permanent magnets, and BLDC require expensive inverter controllers. Plus, even though the best BLDC are maybe 93% (after inverter losses) compared to a 90%, that's on the wrong side of the optimization problem, analogous to Amdahl's Law: Doubling insulation means you need half the energy in the first place, while doubling motor efficiency from 90% to 95% only saves 5%.