Difference Between 4-Wheel Drive & All Wheel Drive

by Richard Rowe

Though similar in principle, the intent of All-Wheel Drive (AWD) and Four-Wheel Drive (4WD) vehicles are very different. One is used for enhancing traction in all situations, while the other is intended specifically for off-road performance.

History

The first four-wheel systems were used on electric cars in the late 1800s, and AWD was first used by Audi in the late 1970s for rally racing.

4WD Purpose

AWD is used to distribute power among all four of a vehicle's wheels for traction.

AWD is a type of 4WD system, and like traditional 4WD, is used to distribute power among all four of a vehicle's wheels for traction.

Difference

AWD uses a center differential similar to those found in the axles to allow the axles to turn at different rates.

Traditional 4WD systems use a transfer case that completely locks the front and rear axles together for better off-road traction. AWD uses a center differential similar to those found in the axles to allow the axles to turn at different rates.

4WD Advantages

Because the axles are locked together, 4WD systems are better for hard-core off roading, rock-climbing and fording mud and water.

AWD Advantages

AWD systems are more geared for on-road handling, and can allow infinite variation of power split between front and rear axles. This allows an AWD car to have the stability of a front-drive car, with the cornering ability of a rear-drive one.