What does all-wheel drive mean?
If you’re shopping around for a car, you will likely hear the terms all-wheel drive, or AWD, used in vehicle descriptions. So what does all-wheel drive mean?
AWD is a computer-based system in the car that automatically distributes power to all four tyres as required for the appropriate traction needed for the surface and speed the car is experiencing.
Does all-wheel drive feel different?
On dry, flat, straight roads you probably wouldn’t notice any difference between an AWD car and a two-wheel drive (2WD) or four-wheel drive (4WD) car.
However, in any other driving conditions, AWD will likely feel smoother and more stable. That’s because an AWD car has more grip, better traction and more precise steering control. So if you’re driving in wet or snowy conditions, or are on a curvy or windy road, you’ll most likely feel more stable and safer in an AWD vehicle.
All-wheel drive vs 4WD
The terms AWD and 4WD are often used interchangeably. But they’re not exactly the same thing. Both systems send power to all four tyres, but they are systems that are used in different conditions.
AWD is good for everyday, all-weather conditions and light off-road driving. It is often found on cars, not just larger vehicles. AWD operates without driver interference – that is, you don’t need to put the car into AWD mode with a switch. The car’s sensors detect when it is needed and when more torque is needed for better traction from all four wheels.
4WD is better for true off-road driving, challenging terrain and when the vehicle needs to work hard – when towing a boat or trailer, for example. It’s usually found in larger vehicles, such as SUVs or utes, and it may need to be set by manually putting the car into 4WD mode.
Which tyres need chains on all-wheel drive?
We always recommend that you check your owner’s manual for things like this. There are differing opinions on whether to put chains on the two front tyres or the two rear tyres.
To be safe, if you’re planning on putting chains on your vehicle, it’s probably best they go on all four tyres to boost traction and optimise steering.
Components of an All-Wheel Drive System, such as the Powertrain, Differential, and Axles
The components of AWD are computer-controlled systems that engage when the vehicle senses particular road surface conditions or power demands.
The components can sense when varying degrees of steering precision or torque are required.
The powertrain is the group of components that moves the vehicle forward. It creates power from the engine and delivers it to the wheels. In an all-wheel drive car, the powertrain can provide power to all of the wheels at the same time.
The differentials are the units with gears, connected to the output shafts that turn the wheels, which let the wheels turn at different speeds when going around curves and corners. With all-wheel drive, there is a centre differential that transfers power between the front and rear wheels as needed.
AWD vehicles have a differential between the front and rear axles because, in a corner, all four wheels will turn at different speeds. The amount of power to each axle can be set electronically to provide a rear-wheel or front-wheel bias.
How an All-Wheel Drive System Operates, Including Power Distribution and Traction Control
In an AWD system, all four wheels, instead of two, receive torque through a set of axles and spin at different speeds simultaneously. AWD systems typically operate without any driver involvement.
They are computer-controlled systems that use sensors to automatically decide which axle and which wheels receive the most power at any given moment when road surface conditions or vehicle dynamics demand extra traction.
Some AWD systems offer a locking differential that equally splits power between the front and rear axles for maximum traction at low speeds.
What is All-Wheel Drive and How Does it Differ from Other Drive Systems?
An AWD system will send torque to all four wheels to maximise traction when needed. This is different from a 2WD system that only sends power to two wheels, either front or rear (FWD or RWD).
There are two different types of AWD: full-time AWD and part-time AWD. Full-time AWD is engaged continuously, while part-time AWD keeps the car in just front-wheel drive or rear-wheel drive until more traction becomes necessary.
Benefits of All-Wheel Drive for Drivers
The greatest advantage of an AWD system is that the driver doesn’t need to manually change anything when the system is needed. The system automatically allocates and maintains torque when needed. Because it’s a computer-based system, it can make quicker decisions than a human could.
If you’re unsure about any feature of an all-wheel drive vehicle, feel free to get in touch with the experienced team at Mt Roskill Collision Centre.