Types of an Automobile layout (Introduction to Automobile Engineering)..!

Front engine rear-wheel drive:

The drive chain in this layout is as follows: Engine → clutch gearbox universal joint propeller shaft differential rear axle wheels.

The following are advantages:

Weight distribution in a vehicle (engine weight is on the front axle, passenger weight is on the rear axle).
Design with a simple steering mechanism for the front axle.
Increased luggage carrying capacity at the rear.
Linkages controlling the engine are short and simple, such as clutches and accelerators.
Access to various engine components is easier.
Taking full advantage of the natural airstream flowing across the radiator will improve engine cooling.
The following are disadvantages its name suggests, this is the most conventional type of layout, and the engine is located in the front of the vehicle, while the drive is transmitted to the rear axle.

Transmission of drive from the gearbox to differential requires a long propeller shaft.
The rear floor houses the propeller shaft, so rear leg space is limited.
There is more noise transmitted from the front engine to the driver's cabin.
As a result of higher weight being transferred on front wheels while decelerating, large brake pads are required at the front wheels.

Rear engine rear-wheel drive:
- This type of layout eliminates the necessity of a propeller shaft.
- The engine is mounted at the rear and drive is also transmitted to the rear axle.
- For this layout, the drive chain is.
- Engine → clutch → gearbox → universal joints → differential → rear axle.
It has the following advantages:
- It consists of a very simple design that houses only the steering mechanism.
- The high weight on the driving axle provides excellent traction and grip on steep hills.
- Due to the lack of a propeller shaft, the rear floor can be made flat.
- The driver's cabin is well isolated from engine noise.
- Due to the elimination of the front engine packaging constraints, the front body can be designed as per style.
The following are disadvantages:
- An engine cannot be naturally cooled by air, so a powerful radiator fan is required.
- Clutch and gear shifting mechanisms are long and complex.
- Due to higher weight concentration at the rear, the vehicle tends to oversteer when taking a sharp turn.
- There is limited luggage space at the front due to a small compartment that houses the fuel tank and spare wheel.
Front-engine front-wheel drive:

The layout is the most compact.

In India, it is popularly used on most hatchback cars.

Refer to Fig. 1.11 for layout for front-engine front-wheel drive.

For this layout, the drive chain consists of Engine → clutch → gearbox → universal joints → differential front axle → wheels

These are the advantages:

A vehicle with a compact design.
As a result of the higher weight of the steering wheels, it provides stable steering during turns.
On slick roads, skidding is reduced.
Propeller shafts are not required.
Since there is no propeller shaft, the rear floor is flat.
As a result of natural air flowing across the radiator, the engine cools better.

The following are disadvantages:

The front-wheel design is complicated because it supports a mechanism. You will find the engine, the differential, and the steering.
Transmission of high noise from the engine compartment to the driver's cabin.
Because of the lower weight on the rear wheel, the vehicle is less capable of climbing steep hills.

4. Four-wheel drive:

In some cases, automobiles with a conventional layout (2-wheel drive) get stuck in potholes while driving on rural or uneven unconstructed roads.
When the automobile gets stuck in a pothole or ditch, it's difficult for the driver to get it out.
In such a scenario, the drive wheel itself can get stuck.
Four-wheel drive trains are used to provide better maneuverability, i.e. drive and traction on all four wheels of a vehicle.
Refer to Fig. 1.12 for a four-wheel-drive layout. (See Figure 1.12 on next page) The drive chain for this layout is as follows:
Engine Clutch-Transfer case* Front axle Front wheels Rear axle Rear wheels.
4WD or all-wheel drive refers to a vehicle with a four-wheel drive. It is possible to engage or disengage the 4-wheel drive by using a lever located in the driver's cabin.

It has the following advantages:

The following are disadvantages:

5. Articulated vehicle layout:

This layout is typically used for very high load carrying vehicles such as trucks with more than 25 T(tonnes) load-carrying capacity.
It is also referred to as a tractor-trailer type of layout.
Refer to Fig. 1.13 for articulated vehicle layout.
It consists of a very heavy and powerful engine at the front (tractor compartment).
The tractor part of the vehicle can be four-wheeled or six-wheeled and consists of the drive axle.
The trailer carries a dead axle at the rear.
By means of a special coupling, the trailer is attached to the tractor.

It has the following advantages:

It provides large luggage/load carrying space. • It greater maneuverability.
The tractor compartment can be easily disengaged and connected to another pre-loaded trailer, hence reduced loading/unloading time.

The following are disadvantages:

Automobile Engineering..!