All Wheel Drive (AWD) & 4 Wheel Drive (4WD)- carengineered.com
Introduction
Earlier we have already discussed the 3 main components of any automobile ie The engine to produce power, The Transmission System to transmit the power, and the Wheel.
We have also discussed various parts and their functioning of the transmission system. So moving forward in this topic we shall be discussing All Wheel Drive (AWD) & 4 Wheel Drive (4WD).
All Wheel Drive (AWD)
As the name implies all-wheel drive is the drive mechanism in which all the four wheels are live ie are powered by the engine. This system is not controlled manually and has a series of sensors and computer interpretations which also vary the magnitude of power reaching each wheel according to the need of the situation for optimized power distribution through various couplings such as differentials or viscous couplings. There are mainly 2 types of All-Wheel Drive:
Full-Time All-Wheel Drive
In this type of all-wheel drivetrain system, all the 4 wheels are all-time being powered by the engine. All 4 wheels are connected and move simultaneously. Mainly used when moving on a slippery surface or high-speed cornering, needing traction.
Part-Time All-Wheel Drive
In this type of all-wheel drivetrain system, the all-time live axles are front or rear depending on the make of the vehicle.
Pros and Cons of AWD
This system is experiencing an increase in demand as manual interpretation and work are negligible. All the main decisions are been taken by the sensors for the best output.
This system is really helpful in muddy areas, sand, slippery areas where extra traction is needed.
Apart from benefits, this system increases the price of the vehicle.
It also decreases the fuel economy of the vehicle.
4 Wheel Drive (4WD)
This system is an old system primarily used in large SUV’S, Trucks, and still continues to be majorly used in the trucks and SUV’S.
4WD systems deliver torque through a series of front, center, and rear differentials, transfer cases, and couplings, which allow the vehicle to operate at maximum traction under a number of conditions.
The 4WD is almost the same as AWD, in which all the 4 wheels gets powered from the engine, but used in more rugged terrain and are much more robust than AWD.
This mechanism also uses a number of sensors or in some cases a manual lever that allows the driver to make decisions on implementing 4WD.
This drivetrain also is of 2 types:
Full Time 4WD
In this mechanism, all the 4 wheels are provided with the power from the engine full time, In some cases, the driver may have an option for managing the amount of power being distributed to all the wheels under various conditions.
Partial 4WD
In this mechanism, initially, only 2 wheels are powered by the engine whether it is front wheels or rear depending upon the make and the model.
The driver makes the decision of fully implementing this system of distributing the power in all the 4 corners of the vehicle through a push button or mechanical lever depending upon the demand of the surface and the condition.
Pros and Cons of 4WD
This system is employed in rough and rugged terrain and perform very well.
More robust system than AWD so widely used in trucks, SUV’S.
Apart from the benefits, this system increases the initial cost of the vehicle.
This system decreases the fuel economy of the vehicle.
Originally published at https://www.carengineered.com on May 28, 2020.
