[Espeefan]

Tinbender, yes, your truck kit does come with a standard issue Tamiya motor. We all call them 'silver cans'. They are decent motors, but they run some pretty high RPMs, and with the Tamiya truck's stock gearing, the truck will be fast. To fast, in 3rd gear. The reason someone recommended a 55T motor is because it helps slow the truck down. Motors are not all the same. A 55T motor is actually a 55 turn motor. The T stands for the number of times the wire wraps around the motor's armature, or we call it the number of 'turns'. So a 55 turn motor has the wire wrapped around the armature 55 times. Think basic magnetic experiments, from your science classes, as a grade schooler. Building an electro-magnet with wire and a metal core, like a nail. Wrap the wire 55 times around the nail and magnetic field becomes stronger. In the case of motors, wrapping a wire 55 times around the armature makes for a slower spinning motor, that also draws less current. Fewer turns makes the motor spin faster. A stock Tamiya motor, if I remember correctly, has 23 turns, so it's going to be a lot faster.

I would suggest looking at the idea of adding a reduction box, like the one from PMD. The link was already posted. It's a nice reducer.