Would they really be that far off from each other? I mean, at the same speed, the two would be pulling the same amount of power from the battery to move the truck. Right? The weight differs a bit with the motors, but I don't think that is enough to affect current draw so much.
well.. depends what kinds of speeds you're talking about....? the KV and Size of the motor both plays a role... if you're geared for 20MPH, they both would be similar... but if you're geared for 40MPH, then the L will definately draw more amps...
Power is RPM * Torque
Torque = Current
Kv defines RPM
Motor size defines motor rated power
If you operate motor outside power envelope -> motor would smoke
If you are going to use within power levels then motor with greater Kv would draw more Amps.