For four-wheeled vehicles, this term is used to describe vehicles that are able to power at most two wheels, referred to as either front or rear wheel drive. The term 4x2 is also used, to denote four total wheels with two being driven.
For vehicles that have part-time four wheel drive, the term refers to the mode when 4WD is deactivated and power is applied to only two wheels.
For two-wheeled vehicles such as motorcycles and bicycles, the term is used to describe vehicles which can power the front as well as the back wheel. The term 2x2 is also used, to denote two total wheels with both being driven. 2x2 vehicles are typically either mechanically driven via chain or shaft or are hydraulic driven. This scheme greatly improves offroad performance, but is quite complicated and requires more power to operate, thus most 2WD machines are either "exotic" bikes for enthusiasts or vehicles created with special uses in mind.
- Two-wheeled vehicles