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 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
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.
References
Writer Bio
Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.
