the 3/1 gears are a necessity for the heavier tanks (especially with metal tracks) but I"m not sure they are really needed for the lighter stugs/panzer III/panzer IV. the white capped motors operate at a lover RPM than the Black cap. a 3/1 gear box with white cap motors is dead slow. You will need to upgrade to either a black cap motor but for best results get a speed 400 motor. Your tank (whatever it is) will be able to climb a wall