[Savage]

As Strongbow points out, much better tyres on newer releases, so I would imagine thats the main difference you have.
Slotcrazy is also on the money for further investigation

The older one may have a different motor, if the plastic end is orange they are the current standard slot.it motors.
Even though it may have a faster rpm rating on a white ended one, you will probably find the orange ones to be quicker to drive