In a motor vehicle that has a four-wheel drive system, power can be transmitted to four road wheels instead of two. Each manufacturer has their own chosen mechanism to provide power to all of the wheels. Generally there are two distinctive ways that four-wheel drives work.

A part-time four wheel drive only gives power to all four wheels if slipping is detected on the two main driving wheels. The part time system is employed for use when low-traction conditions such as off-road, snow or ice are encountered; otherwise the power runs through the two main driving wheels.

A full-time 4-wheel-drive obviously gives power to all four wheels and is usually designed to function on all types of surfaces, both on- and off-road. Most of full-time four wheel drive systems cannot be switched off.

Part-time and full-time four-wheel-drive systems can be evaluated on how well the system gains traction. And the best four wheel drive system will send exactly the right amount of torque to each wheel so that tyre slip is kept to the absolute minimum.

The main parts of any four-wheel-drive system are the two differentials (front and rear) and the transfer case. In addition to this, part-time systems have locking hubs. And both types of system may have advanced electronics and systems in place that enable greater levels of traction to be achieved.

Owning a four-wheel drive vehicle is an enjoyable experience. Four wheel drive vehicles not only are capable of going some places you otherwise couldn’t get to, but they can also offer a commanding driving position on-road.

What are the best four wheel drives in the business? For ultimate traction, the Land Rover and Hummer rate as the best vehicles in the business for gaining traction off-road and in slippery conditions.

Four-wheel drive vehicles are also called 4x4s.

We hope that helps answer the question ‘What is What is a Four-Wheel Drive?’!

Back to Car Glossary