Acceleration

Acceleration is a stat in all of the Mario Kart games. Depending on the weight and size, the kart can either have good or bad acceleration. If a kart is light and small, it will have faster acceleration. If the kart is heavy and big, it will have slower acceleration.

Bigger and heavier characters can obviously only fit in big karts. Therefore, those characters are expected to drive with slow acceleration, for the most part. Smaller and lighter characters can only drive small karts, and therefore are expected to drive with faster acceleration, for the most part.

There are exceptions to this, though. For example, in Mario Kart: Double Dash!!, karts like the Boo Pipes are big and heavy, but have fast acceleration.