All Wheel Drive (or AWD) is a system in which all four wheels of a car operate simultaneously to improve traction and handling. While it is possible for a car to have continuous AWD capabilities, it is far more common for one pair of wheels to engage only when sensors detect that the other pair has begun to slip. There are both advantages and disadvantages to AWD systems
In intermittent AWD systems, the rear wheels engage when sensors detect slippage from the front wheels. Under these circumstances, the vehicle effectively detects and compensates for dangerous driving conditions such as standing water, snow, ice or gravel that could otherwise compromise control of the vehicle. By engaging the second set of wheels, the vehicle experiences two additional points of contact on the surface of the road, allowing greater likelihood that its tires will grip the surface and allow the driver to retain control. The additional weight of AWD systems also encourages more grip on the road and the added points of contact distribute the vehicle's weight more evenly over points of propulsion.
The primary disadvantage of an AWD vehicle is its cost. The drive train and related equipment necessary to provide both continuous and intermittent AWD is complex and expensive, often requiring sensors and computers that are not necessary on two- or four-wheel-drive vehicles. This cost increases the initial market value of the vehicle and can also affect the cost of repairs. In addition to these costs, AWD systems require more fuel to power the additional wheels and are less fuel efficient than comparable two-wheel-drive vehicles.
Braking Distance and Collision Avoidance
While the weight of AWD vehicles improves their handling, it also increases the distance they require to stop. In a scenario where the vehicle must make a sudden stop and cannot swerve or turn, a collision becomes more likely than with a lighter car. Under similar circumstance, but ones in which an accident can be avoided by turning, AWD vehicles offer superior collision avoidance than similar vehicles with less effective handling and turning capabilities.
- Photo Credit Small All Terrain Vehicle on a beach image by Sergey Sukhorukov from Fotolia.com
Subaru All Wheel Drive Technology
Subaru's all-wheel drive technology stands apart from other AWD and four-wheel drive (4WD) systems. Despite the potential for confusion, AWD and 4WD...
What are the Benefits of All Wheel Drive?
All-wheel drive, which usually refers to vehicles with full-time four-wheel drive systems, can be an extremely useful feature in cars, trucks, and...
4-Wheel Drive Vs. 2-Wheel Drive
Many different types of vehicles including pickup trucks, SUVs and even some cars boast about including four-wheel, or all-wheel, drive. This system...
What Is All-Wheel Drive?
All-wheel drive (AWD) is a hot-ticket item in today's auto market, and is offered as an option on many cars. The system...
The Advantages of 4x4 vs. AWD
The advantage of a 4X4, or four-wheel drive, over all-wheel drive is that drivers can operate a 4X4 in rough terrain. All-wheel...
Differences Among 4WD, AWD and 2WD
Its a debate nearly as old as the automobile itself, but didn't really come to light in the public mind until the...
What Is the Difference Between a Trailer & a Motorhome?
Recreational vehicles or RVs populate the nation's highways in larger numbers when the spring and summer driving seasons get underway. These vehicles...
Front Wheel Drive vs. Rear Wheel Drive Advantages
Manufacturers, mechanics, car enthusiasts, and consumers, have long debated the rear-wheel drive versus front-wheel drive issue. Determining which vehicles tend to handle...
What Are the Disadvantages of Driving a Car?
The automobile rose to prominence during the 20th century and is now a staple of personal transportation. While driving a car is...
The Advantages of 4X4 Cars
Vehicles are tagged 4-by-4 for the reason that all of its four wheels are capable of receiving torque from the engine at...