What is All-Wheel Drive?
All wheel drive vehicles
All-wheel drive (AWD) refers to a drivetrain configuration where all the wheels of a car receive power from the engine. The term is usually used on four-wheeled vehicles and is sometimes used interchangeably with 4-wheel drive (4WD). An AWD configuration is commonly seen on off-road vehicles because it can add stability and traction when driving on rugged terrain.
In the automobile industry, there is some confusion on the difference between an AWD and a 4WD. It may be because the modern use of these two terms is different than how they were used in the early years of the car industry. To stop the confusion, car manufacturers try to separate these two terms.
Today, all-wheel drive is a configuration where the engine permanently provides power to all four wheels. Cars with this configuration cannot switch to a 2-wheel drive (2WD) mode unlike 4-wheel drive cars. These cars feature a system that controls how much power is provided to the wheels to make it more fuel-efficient on paved roads. Although the term is used mainly with cars, it may also be used on vehicles with more than four wheels.
The AWD drivetrain configuration is commonly seen in vehicles like sports cars, pickup trucks, and some SUVs. Since sports cars are meant to run at a very fast speed, this can prevent a skidding during a sharp turn. Pickup trucks are designed to run on rough road and carry a lot of load. An all-wheel drive system can prevent a pickup from slipping or toppling over. Since SUVs are sometimes used like pickup trucks, they may also come with an AWD system. Most of these vehicles have an improved car suspension system to complement this configuration.
An all-wheel drive configuration works by connecting both axels of a car to the engine with one or more differentials. Differentials are used to distribute the torque and angular velocity between the two axles. These forces are regulated such that when a car turns, the speed of the rear wheels is different from the speed of the front wheels but the torque remains the same. This improves the car’s stability and handling when turning. Slipping is also prevented because of the even distribution of power.
However, AWD cars have difficulty recovering from slipping unlike 2WD cars. When one of the wheels of an all-wheel drive car slips, this wheel will turn faster than the other wheels. The differentials of the car will reduce torque on all other wheels to match the torque of the front wheel. The decrease in torque results to a decrease of power on the wheels, and this makes maneuvering the car difficult.
An all-wheel drive car can be very useful when you live in places where there are snowy seasons. Because this type of car regulates the power that is used on the wheels, it does not consume too much fuel when it runs on paved roads. When it runs on uneven terrain, the power delivered to the wheels is increased. This makes it easy for the car to move on rough or snowy roads.