Four Wheel Drive (4WD)

Also known as 4 x 4.

A part time system by which all four wheels are driven at the same time to provide superior traction in slippery conditions compared with front or rear-wheel drive. When the system is not being used, the vehicle usually has a two-wheel drive setting that only drives the rear wheels. 4WD often comes with a low-range gear setting and locking differential for improved poor weather or off-road traction.

Most commonly found in pickup trucks and full-frame SUVs, four wheel drive adds to the car's weight and increases fuel consumption compared to an equivalent two-wheel-drive car.

See also All Wheel Drive, Rear Wheel Drive and Rear Differential Lock.