18 Major Automobile Components and Their Functions.

Automobile Engineering is a complex and exciting education in engineering. I will discuss 18 major automobile components and their functions in this article.

Automobile Components and Their Functions.

Automobile Components and Their Functions.

Before you start reading this article, please take a good look at the Fig. In this Fig., you will get the details of every part of the component in a vehicle. 
Various other parts shown in the vehicle are- the steering wheel, universal joints, gearbox, propeller shaft, and others. So the major automobile components are- 
  1. Engine.
  2. Lubrication System.
  3. Cooling System.
  4. Fuel System. 
  5. Ignition System.
  6. Electrical System.
  7. Frame.
  8. Suspension System.
  9. Power Train.
  10. Clutch.
  11. Transmission.
  12. Drive Shaft.
  13. differentials.
  14. Axels.
  15. Wheels.
  16. Steering System.
  17. Breaking System.
  18. The Car Body.

1. Engine

Engine parts.
Engine parts


The engine is a device used in the vehicle to provide the vehicle power to operate the functions in the vehicle. In automotive engines, the combustion of air and gasoline drives the pistons. The pistons then turn the crankshaft(attached with the connecting rod) to which they are attached. The rotating force of the crankshaft makes the automobile’s wheels turn. 
Some automobiles are powered by another kind of engine known as a rotary valve, rotating combustion engine, or wankle engine. The rotary valve engine also known as the wankle rotary engine, draws in a mixture of air and fuel, which is then compressed and burnt. In a vehicle, the engine is mounted either at the back or neither at the front end, with the clutch and gearbox immediately behind it; the engine, clutch, and gearbox are assembled in a single unit. 
The engine works on many components. The lubrication system, cooling system, ignition system, and many other circuits and other options are worked on the engine. Every system is discussed below.
The ignition system is worked on the principle of atmospheric pressure. The air and fuel mixture enters the cylinder and the combustion of these components drives the system. Finally, an electrical system is required to operate the cranking motor that starts the engine and provides electrical energy to power engine accessories.

2. Lubrication System

Lubrication system.
Lubrication system diagram.


An engine is a mixture of moving parts, which need a perfect frictionless place to operate. The lubrication system circulates oil between these moving parts to prevent metal-to-metal contact, resulting in wear. The moving parts that are oiled can move more easily with less friction and hence power loss due to friction is minimized.
A lubrication system is also used to act as a cooling media and as a sealing medium to prevent leakages. Finally, a film of lubricant on the cylinder walls helps the rings in sealing and thus improves the engine’s compression.

3. Cooling System

Cooling System.
cooling system diagram


Due to the combustion of air/fuel, inside the cylinder, the temperature of the engine parts increases. The increase in temperature directly affects the engine performance and the life of the engine parts. The cooling system helps the engine to operate at an efficient temperature. Whether the driving conditions, the cooling system is designed to prevent both overheating and overcooling. 

4. Fuel System

Fuel System.
Fuel system diagram


The main function of the fuel supply system is to provide fuel to the carburetor or the injection system at a rate and pressure sufficient to meet engine demands under all conditions of old, speed and gradients encountered by the vehicles. The fuel system also has a reserve system that helps the car to move a little more while the level is low.

5. Ignition System

Ignition System
Ignition system diagram.


The Ignition system provides the car assistance for the combustion of fuel. It can be done either by a high-voltage spark or by self-ignition of each of the engine’s cylinders at the right time so that the air-fuel mixture can burn completely.
The fuel and air delivered to the combustion chamber must be ignited to deliver the power. In a spark ignition engine, an electrical spark is used for this purpose. The compression-ignition engine does not require a separate ignition system because the density of the fuel makes the fuel burn as the temperature rises. 

6. Electrical System

The engine’s electrical system allows the engine to operate a starting motor and to power all the accessories. The components of the electrical system are-
  1. A battery
  2. An alternator
  3. A starting motor
  4. Ignition coil
  5. Heater. 

7. Frame

The frame is the foundation for the engine and body of the vehicle. The frame is constructed from square or box-shaped steel members strong to support the weight of the body and other components. 
The vehicle frame(also called chassis) is usually made up of several members welded or riveted together to give the final shape. The engine is mounted on the frame with rubber pads which absorb vibration and also provide damping of these vibrations. Absorptions and damping of vibration protect passengers from discomfort caused by shocks. The chassis is supported on wheel axles using springs. 

8. Suspension System

Suspension System.
Front-end suspension system diagram


Suspension systems are used in automobile vehicles to absorb road shock. When the vehicle hits any bumper or potholes the up and down movement of the vehicle is controlled by the suspension system. Swing bar, and springs connection linkages are the components of the Suspension system. This is all systems working together to absorb the major shock coming out from the road. The suspension system is of two types- 
  • Rigid System.
  • Independant System.
In the Rigid system, all the springs are connected to the vehicle chassis with a Rigid action. It is used mostly in older cars and tends to buckle up. Also, this system has the disadvantage to the absorb the road shock, and performing the same for all the wheels.
In an Independent system, it does not have a rigid axle. Every wheel can move freely and vertically without any reaction on its primary wheel. The independent system is mostly used in small cars.

9. Power Train

The power train is the carrier of the engine power to the various parts of the system. It consists of the clutch(on cars with manual transmission), transmission(a system of gears that increases the turning effect of the engine to move the automobile), drive shaft, differential, and rear axle.

10. Clutch

The clutch is used in the system to engage and disengage the engine power with the transmission. The engagement and disengagement of the power varies the transmission to change the gear ratio.

11. Transmission

The function of the transmission system is to provide the necessary variation to the torque applied by the engine to the wheels. The transmission system changes the gear ratio between the engine output shaft and the drive shaft.

12. Drive Shaft

The drive shaft is called the propeller shaft. This connects the gearbox and the differential unit. The drive shaft has universal joints at its ends. 

13. Differential

The differential is used to split the power, that is received from the propeller shaft to the rear axle shaft. This system allows the rear wheels to be driven at different speeds when the vehicle takes a bend or falls into a ditch.

14. Axles

The axle is an important component used in the automobile sector on which the road wheels are mounted. It also transmits driving torque from the engine to the wheels, allowing the vehicle to move.

15. Wheels

The wheels in the automobile sector are used to take the load of the vehicle and also produce tractive force to move the vehicle. The wheels are also used for retardation and stopping the vehicle. 

16. Steering System

Steering system
Rack and pinion-type steering system


The steering system is the crucial component used for changing the direction of the vehicle. The major requirements in any steering mechanism are that it should be precise and easy to handle and that the front wheels should have a tendency to return to the straight-ahead position after a turn. A gear mechanism, which is known as the steering gear, is used in this system to increase the steering effort provided by the driver. This system makes vehicle steering very easy as the driver does not have to put in much effort. Vehicle steering is not only required on a curved road but also while maneuvering on busy traffic roads. The steering system allows the vehicle to be guided i.e., to be turned left or right. 

17. Braking System

Braking system.
Braking system diagram.


Breaks are required for stopping or slowing down the moving vehicle. The braking system is essential for the safety of passengers, and passersby on roads. The braking system may be operated mechanically or hydraulically. 95% of vehicles use hydraulic braking systems now.
All brakes consist of two members, one rotating and the other stationary. There are various means by which the two members can be brought in contact, thus reducing the speed of the vehicle.
The major system of braking systems is – the brake pedal, master cylinder, wheel cylinder, brake drum, brake pipe, brake shoes, brake packing plants, and linkages. As the load on the vehicle and the vehicle speed have increased according to recent trends in modern days, the importance of the brake system has also increased and power brakes are now being preferred. Power brakes utilize vacuum and air pressure to provide most of the brake-applying effort. 

18. The Car Body

The main purpose of the bodywork is to provide accommodation for the driver and passengers with suitable protection against wind and weather. The degree of comfort provided depends upon the type of car and its cost. 
The body of the first automobiles was little more than a platform with a seat attached. It Gradually developed into a closed compartment complete with a roof and windows. The modern automobile body is constructed of sheet steel formed to a required shape in giant punch presses. Most of the body components are welded together to form a light-rattle-free unit.


The automotive sector is a sector where all the accessories have different roles. The other components include self-starter driving and signaling lights such as headlights, tail lights, brake lights, parking lights, windshield wipers, horns, indicators, and other essential components.
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