2 pole vs 4pole motor torque?..

[nativepaul]

To make a 1520 with the same KV as the 1515, they will use less turns of fatter wire, this fatter wire has less resistance and leads to better efficiency at high amp levels, also the fatter wires and bigger thermal mass mean it is capable of more amps than the 1515. So it it capable of delivering more torque than the 1515 and more efficient when producing it.

It is not a win win situation however. The bigger magnets of the longer 1520 rotor are harder to spin increasing the no load current and making it less efficient than the 1515 at low power levels when it is not producing all the torque it is capable of.

Which is more efficient depends on what you are driving, your gearing and your driving style.

In relation to the title question, the higher the pole count the harder the motor will try to achieve its unloaded RPM when loaded, (assuming similar quality for the motors and the same KVs the KTs (torque/amp) will be similar) they will draw more amps doing so.