They are not remote controlled. They are designed to run free in a guided track. I really didn't pay much attention to the different models, I just looked at the motor's endbell cover and bought the orange ones. (2.6) They have different bodies/gearing/tire combinations. So if you choose carefully, you can score some spare tires as well. I have some of the white rubber tires, but they don't seem to grip well on a smooth surface.