What are All-Wheel Drive Cars?

All-wheel drive is an increasingly common option on vehicles ranging from cars to minivans. However, before you check the option box marked "AWD" it would be wise to learn about its operation and uses.

Definition

All-wheel drive is often referred to by its acronym AWD. AWD is a system that seeks to combine the advantages of both two- and four-wheel drive.

Components

Vehicles with all-wheel drive have several unique components, including a transfer case and center differential, two drive shafts, two axle differentials, and two powered axles.

Technology

All-wheel drive cars use sensors that determine wheel spin. If wheel slippage is detected power is diverted to or away from the wheel to regain traction.

Operations

Many all-wheel drive vehicles actually operate in either front or rear wheel drive mode until wheel spin is detected. This saves fuel and increases the life of the all-wheel drive system.

Benefits

All-wheel drive can enhance a road going vehicles ability to operate in inclement weather such as rain and snow. Additionally, all-wheel drive can greatly reduce wheel spin and improve the acceleration times of vehicles with high powered engines.

Considerations

While all-wheel drive enhances a vehicles traction it also decreases fuel economy. All-wheel drive cars are more costly to manufacture and this increased cost is usually reflected as a higher vehicle purchase price. Additionally all-wheel drive systems can be expensive to repair.