[Al Skierkiewicz]

Paul,
I was suppporting your claims without having gone through the math. As an electrical guy I was just trying to express my way of looking at the premise that would make sense to someone who wasn't following the math. But the friction we are talking about has another side and that being, if you were trying to drive through a different surface, mud for instance, the rolling friction is very high and therefore requires more driving force. (soft tires on carpet would be the same type of rolling friction)
However, limiting to 30 amps on the drive motor would not get you going. I was experimenting with a bare, in my hand FP motor, on a hard regulated supply capable of 25 amps continuous and kept shutting the supply down just trying to get the motor to turn. Instantaneous current is very high on this motor and when in a drive train may actually exceed 100 amps in real world starting conditions.