[Don Wright]

Find a place with carpet like the field and a wall (or some other immovable object).

Put your robot against the wall (or object).

Try to push the wall.

If your tires break loose, adding more CIMs won't do anything for you since you already can't put your power to the ground. Work on traction instead.

If they don't break loose, then worry about adding more power by adding motors.

A 10 motor drivetrain doesn't do any good if you can't put more than 2 motors worth of power to the ground.

IMHO of course...