[Serum]

Thanks for the links! makes searching a bit easier.. :p

to answer your question;
Because of the permanent magnets that are missing.

As you can see; they claim a 92 percent eff. with a star, that star indicates that that efficiency is calculated (in which they admit that they didn't took all the variables in their calculating, and it will probably be lower) A proper brushless motor does a 94 eff at full load.

Now in terms of power;

this is impressive! a 67 kg motor producing over 500 bhp.

Now a little weird but understandable theory;

67 kg, that is 67/1.6= 41.9 Lehner 3080 motors, which are capable of doing 11kW per piece. As you know; the bigger the motor, the more efficient it becomes. and the better the weight/produced power ratio becomes.

Knowing this, 42 LMT3080 motors produce 462kW (630 bhp)

The point is; nothing beats brushless, here are some other facts you might like on the 42 LMT3080 motors;

Torque; (weight/torque ratio)

1 Lehner 3080 produces 7.4 N/m of torque at 42000 rpm. (94.6 percent eff. at this load) (Reduced with a gearbox to 6500 rpm, that would be a 6.46 factor) 6.46*42*7.4=2007N/m@6500 rpm of torque per 67 kg motor.

Not bad either, right? :017:

Considering it are all loose motors