Understanding Basic Car Wheel Drive Systems

A wheel drive system is a combination of simple components that helps and supports the movement of the wheels in a car. The first wheel drive system is as old as the first car itself. Over the years, as cars have evolved into more complex machines, so have wheel drive systems grown in sophistication to the point of being identified as an individual science in car engineering. This has resulted in each unique type of wheel drive system being identified by a different name and classification based on its inherent characteristics.

The most basic such classification of car wheel drive systems is based on which set of wheels (front or rear) it drives. As confusing as the terms front wheel drive and rear wheel drive in a car may seem, the basic concept behind them is pretty simple.

Here is a brief introduction of the two types of wheel drive systems:

Front Wheel Drive (FWD)

In a front wheel drive car, the transmission system is connected only to the two front wheels of the car. All the power generated by the engine is used to drive only these two front wheels. The rear wheels act as dummies whereby their only purpose is to support the rear portion of the car and they just roll around to keep the car moving forward as the engine forces the front wheels to rotate. In a car with FWD, the entire drive mechanism including the engine and car transmission systems is located to the front of the car. Most cars in India come with a front wheel drive configuration due to their simplicity in structure and low cost of assembly.

Rear Wheel Drive (RWD)

A rear wheel drive system is the opposite of front wheel drive. In this type of drive system, the engine and transmission system drive the two rear wheels of the car instead of the two front wheels. So, when a driver presses the accelerator, the rear wheels are made to move by using engine power. Except for a few cars, the engine in a rear wheel drive car is located to the front of the car too but the transmission system is linked to the rear wheels. This type of drive system is mostly used in racing cars and performance cars it can accelerate better on dry roads.

As can be clearly interpreted, each of the above wheel drive systems has advantages and disadvantages of its own. There have been a lot of debates as to which is better. Not to say that they are not existent now but rear wheel drive cars were more common in the past. By the early 1980s, front wheel drive cars started gaining popularity and soon found themselves on most passenger cars. Today, the car model line-up of many car manufacturers includes several with FWD and a few with RWD.

Here are some of the advantages and disadvantages of each drive system:

Advantages of Front Wheel Drive over Rear Wheel Drive

· FWDs are not very expensive and can be easily installed in a car but in case of rear wheel drive the production and assembly is expensive.

· Designers tasked with upgrading a car model can easily locate other parts beneath the car such as brake lines, fuel lines, and exhaust system whereas the rear wheel drive has a complex structure.

· The weight of a FWD configuration is comparatively less than a RWD. Reducing a car's weight benefits fuel economy and enables better braking.

· Provides better road grip than an RWD on slippery roads.

· Cabin space and trunk space in the car are relatively more as no large mechanical parts are links to the rear wheels.

Advantages of Rear Wheel Drive over Front Wheel Drive

· In a RWD system, as some of the mechanical parts are removed from the front of the car and moved to the rear, the weight distribution is better between the two ends of the car. This enables improved handling. FWD provides comparatively less handling.

· Making use of the rear tires for acceleration and traction takes load off the front and drivers accelerating around a corner get better side grip. In case of FWD the road grip of the rear tyres is reduced.

· Repair costs are much cheaper when compared with front wheel drive system.