This document provides an overview of automobile classification systems. It begins by generally classifying vehicles as single-unit vehicles or load carriers and articulated vehicles. It then discusses axle classification systems using letters to denote driving and non-driving axles. Specific types of automobiles are also classified based on use, capacity, fuel used, make and model, wheels/axles, drive type, engine, suspension, transmission, and body style. Common body styles like sedan, hatchback, and SUV are defined. The document concludes with a brief overview of crash testing and the evolution of automotive safety features.

1. Classification of Automobiles
ME3103: Automotive Engineering I
Department of Mechanical Engineering,
Faculty of Engineering,
General Sir John Kotelawala Defense University

2. • General Classification of Vehicles
• Types of Automobiles

3. General Classification of Vehicles
1. Single - unit Vehicles or Load carriers
2. Articulated Vehicles

4. Axle Classification
• Driving axle denote by letter “x”
• Non Driving axle denote by letter “o”
– ox – conventional four wheeler
– xo – front wheel drive four wheeler
– xx – four wheel drive four wheeler
– oox – six wheel drive with two steering axles
– oxx – conventional six wheeler
– xxx – six wheel drive six wheeler
– ooxx – conventional eight wheeler with twin steering
axle

5. Single - Unit Light Veh or Load carriers
• Car, Van, Truck, Bus, Coach
• Conventional 4 wheel type
• Majority with 2 axle design
– Front axle Driving
– Rear axle Driving
• Ex
– 4x2, 4x4, 6x4
(First figure denotes total no of Wheels, Second
Driving Wheels)

6. • Heavy Tractors
• Motor coaches
• Lorries
• ox, oxx, xxx, xxxx

7. Articulated Vehicles
• Heavy load carrying & Tractors & Semi Trailers. Only tractor provides
the motive power while trailer carries the goods. Two units
connected by ‘fifth wheel coupling’
• ox, xx

8. Types of Automobiles
1. With respect to the Use
2. With respect to the Capacity
3. With respect to the Fuel used
4. With respect to the Make & Model
5. With respect to Wheels & Axles
6. With respect to the Drive
7. With respect to the Engine
8. With respect to the Suspension
9. With respect to the Transmission
10. With respect to the Body style & no of Doors

9. Types of Automobiles
1. With respect to the Use
• Scooters & Motor cycles
• Cars Station wagons, pick-ups & Vans
• Lorries, Buses & Trucks
• Tractors
2. With respect to the Capacity
• H.T.V. – Heavy Transport Veh
• L.T.V. – Light Transport Veh
• ¼ Ton, 1 Ton, 3 Ton
• 2 seater, 5 Seater, 52 Seater

10. Types of Automobiles
3. With respect to the Fuel used
• Steam
• Petrol, Diesel, Gas
• Electric, Hybrid
• Hydrogen

11. Types of Automobiles
4. With respect to the
• Make - Name given by manufacturer. After the name, name
of the power unit indicating, no of cylinder, shape of the
engine.
• Toyota, Nissan, Dihatsu
• Land Rover, Jaguar, Ford, Ferrari, Renault….
• Bajaj, Honda, Yamaha, Kawasaki
• Layland, Tata, Mahindra
Model - The Year of manufacture or Specific code no
• Toyota – Corolla AE100, 110, 121, CE100, CE110
• Nissan – Sunny FB13, 14, 15, SB 13, 14, 15
• Yamaha – FZ, DT, TW, TTR, R1, FZR

12. Types of Automobiles
5. With respect to Wheels & Axles
• Two wheelers
• Three wheelers
• Four wheelers…. With Axle Classifications
6. With respect to the Drive
• Left hand drive
• Right hand drive
• 2 wheel drive, 4 wheel drive, 8X8

13. Types of Automobiles
7. With respect to the Engine
• External combustion engine.
• Internal combustion engine.

14. • External combustion engine.
• steam engine

15. • Internal combustion engine.
• Reciprocating engine
4 stroke engine
2 stroke engine
• Rotary engine
Wankle engine
Turbine engine
• Reaction engine
Rocket engine

16. 8. With respect to the Suspension
• Conventional
• Spring, Shock-absorber
• Independent
• Pneumatic, Self leveling
9. With respect to the Transmission
• Conventional (Manual)
• Automatic
• Semi Automatic
Types of Automobiles

17. Types of Automobiles
10. With respect to the Body & no of Doors
• Microcars
• Saloons/ Sedan
• Convertible
• Station Wagon
• Coupe
• Hatchback
• Sports
• Off-roaders
• Multipurpose Veh/ Mini van

18. Main components & Assemblies
(Constructional Features)
1. The Basic structure or the Framework
2. The Engine or Power plant
3. The Power train or the Transmission sys
4. The Body or the Super structure
5. The Auxiliaries
• Fuel, Lubricant, Cooling, Brake, Exhaust
6. The Controls
• Clutch, Brake, Accelerator pedals
• Lighting Switches
• Viper, AC switches

19. Layout of an Automobile
• Different veh to veh

20. • Frame, Chassis
• Superstructure, Body
• Front axle
• Rear axle
• Wheel
• Suspension system
• Power unit
• Transmission system
• Brakes
• Electrical system
• Safety systems
• Auxiliaries
• ECU & controlling modules

21. CHASSIS
BASIC FUNCTION OF CHASSIS ARE
1. Provide basic structure to assemble body or super structure and all
other components.
2. It absorbs the reaction from the movement of an engine and axle.
3. Balances the reaction forces (Twisting & Bending forces) of the wheel
in acceleration and braking.
4. Absorb aerodynamics wind forces and road shocks through the
suspension.
5. Absorb the major “Energy of Impact“ in the event of an accident.

22. Basic structure
• Wheel track
• This is the transverse distance between the tyre to ground centers on the near-
side & the off-side.
• Wheel base
• This is the longitudinal distance between the centers of the front & rear axles
• Ground clearance
• This is the vertical distance between the lowest place of the vehicle body to the
ground.

23. • Side rails – runs from front to rear on each side of the veh & support the
body
• Control beam stiffness
• Control the tortion
• Control the vibrations
• Cross members – separate the side rails & support other sub-systems
• Welded, bolted or reverted
• Transfer inertia force from components to side rails
• Fuel tank, rear suspension, radiator, spare tyre
• Brackets – provide a means for attaching the various sub-systems
• Welded to side rails or cross members
• Components mounted with bolts with rubber mounts or bushings

24. Different Type of Chassis
1. Ladder Chassis
2. Backbone Frame Chassis
3. Tubular Frame Chassis
4. Monocoque Chassis
5. ULSAB Monocoque

27. Ladder Chassis
• This is oldest kind of chassis.in early 60s,nearly all cars in world used it
as a standard chassis. Even today most of the SUVs & MUVs use this type
• COSTRUCTION
• As name is LADDER : it has two longitudinal rails interconnected by several
lateral and cross braces. The longitude members are main stress member. They
deals with the load and also the longitudinal forces caused by the acceleration
and braking. The lateral and cross members provide the resistance to the lateral
forces and further increase torsional rigidity.

30. • ADVANTAGES
1.Easy to construct
2.Good for SUVs & truck
DISADVANTAGES
Torsional rigidity is lower especially in case of vertical loads and
bumps.
USED BY
Truck making company like TATA, ASHOK LEYLAND.

31. 2. BACKBONE FRAME CHASSIS
• This is also one of the oldest type
of chassis.

32. TATRA

33. • CONSTRUCTION
It is usually in rectangular section connects the front and rear axle and
provides nearly all the mechanical strength. Inside which there is space
for the drive shaft in case of front engine, rear-wheel drive. The whole
drive train, engine and suspension are connected to both ends of the
backbone. The body is built on the backbone, usually made of glass-fibre.
• ADVANTAGES
1.Strong for smaller sports car & used by special Heavy veh
2.Easy to construct by hands
3.Cheap for low volume production

34. • DISADVANTAGES
1.Not strong enough for high-end sports car
2.It does not provides protection against side impact
3.Cost ineffective for mass production
3.High Cost for Heavy veh & complex transmission design
• USED BY
• TVR, Marcos
• TATRA

35. 3.TUBULAR FRAME CHASSIS
• As ladder chassis is not strong enough, motor racing engineers
developed a three dimensional design-tubular space frame.

36. CONSTRUCTION
• Tubular space frame chassis employ dozens of circular-section tubes, but
some may employ square-section tubes for easier connection to the body
panels, but remember circular section provides the maximum strength,
position in different direction to provide mechanical strength against forces
from anywhere.

37. • ADVANTAGES
1.It can counter-balance stress from any direction( compared to ladder and
monocoque chassis of same weight)
• DISADVANTAGES
1.Very complex structure
2.Cost and time consuming to built.
3.Impossible for robotized production
4.It also covers lot of space
• USED BY
• Lamborghini , Jaguar XJ22O,ETC

38. 4.MONOCOQUE CHASSIS
• Monocoque, meaning 'single shell' in French, is a construction
technique that utilises the external skin to support some or most of
the load.

39. 4.MONOCOQUE CHASSIS
• This is as opposed to using an internal frame or chassis that is then
covered with cosmetic body panels.
• Today, 99% cars produced in this world are made of steel monocoque
chassis, due to its low production cost and suitability to robotized
production

40. CONSTRUCTION
• It is one-piece structure which defines the overall shape of car. While
ladder, tubular space frame and backbone chassis provides only the
members and need to build the body around them where-as the
monocoque chassis is already incorporated with the body in a single
piece. In fact the "one-piece" chassis is actually made by welding several
pieces together. The floor pan, which is the largest piece, and other
pieces are press-made by big stamping machines. They are spot welded
together by robot arms in a stream production line.

41. • ADVANTAGES
1. Cheap for mass production
2. Proves good in times of crash in case of protection
3. Space efficient
• DISADVANTAGES
1. Impossible for small-volume production
2. Heavy
• USED BY
• All cars, all current Porsche, Audi

43. ULSAB MONOCOQUE
(Ultra Light Steel Auto Body)
• Basically it has the same structure as a conventional monocoque. The
difference is the use of “Hydroform" parts, sandwich steel and laser
beam welding.

45. CONSTRUCTION
• Hydroform is a new technique for shaping metal to desired shape,
alternative to pressing use a heavy-weight machine to press a sheet metal
into a die, this inevitably creates inhomogeneous thickness result the edges
and the corner are always thinner than surfaces. To maintain a minimum
thickness there for the benefit of stiffness, car designer have to chose thicker
steel metal than originally needed.
Conventional sheet metal forming
https://youtu.be/ivEovm9rJcg

46. Hydroforming
• Video- https://www.fluidforming.de/fluid-forming/prinzip

47. CONSTRUCTION
• HYDROFORM technique is very different. Instead of using sheet
metal than originally needed. Hydroform technique is very
different instead of using sheet metal, it forms thin steel tubes.
The steel tube is placed in die which define desired shape, and
then fluid of very high pressure will be pumped into the tube
and then expands the latter to the inner surface of the die. since
the pressure of the fluid is uniform, thickness of the steel made
is so uniform. As a result, designer can use the minimum
thickness steel to reduce weight.

49. • ADVANTAGES
1.stronger and lighter
2.more efficient than conventional monocoque
• DISADVANTAGES
• High cost for equipment
• USED BY
• Opel astra, BMW 3-series
• Most of modern cars

50. Body
• Made of steel, aluminum, fiberglass, plastic, or composite materials
• It forms the outside of the vehicle & Serves as an attractive covering for
the chassis
• For passengers protection & keeping them dry and shaded, the primary
purpose is to shield from the wind, which can be substantial when
travelling at high speeds.
• The body has design with aerodynamic shape
• Has design aesthetically pleasing ways to capture bigger market.
• The body can be based on a chassis but there are also cars of monocoque
construction where the structural loads are distributed throughout the
body, which acts as a load-bearing shell.

51. Body Structure

52. Unibody Construction
The frame is an integral part of the body

53. Body-over-Frame Construction
The body bolts to a thick steel frame

54. Major Body Sections
• Front section (Nose section)
• Between Front bumper & Firewall ( Front uspension parts, Frame rails,
radiater core support)
• Center section
• Mid section (passenger compartment, floor pan, roof pannel, cowl, doors,
door pillars, glass )
• Rear section
• Tail section ( Trunk & lid, quarter panels, rear frame rails rear bumper)

55. Different Type of Body Construction
Classification according to the mounting on the chassis,
1. Conventional Body-Over-Frame construction
2. Unibody construction

56. Conventional Body-Over-Frame construction

63. Unibody

65. Body Types
• Automobiles are available in several body types, according to its
shape, including:
• Micro car
• Sedan/ Saloon
• Coupe
• Convertible
• Hatchback
• Station wagon
• Sports & SUV
• Multipurpose Veh, Mini van, MUV
• Off-roaders

69. Microcars
With modern concepts of lesser space & greener transportation,
microcars became very famous

70. Sedan/ Saloon
Uses center body pillars, or “B” pillars,
between the front and rear doors. A
hardtop does not use “B” pillars.

71. Coupe
• Benz S-Class Coupe
• Subaru Impreza
Coupe

72. Convertible
Uses a vinyl or cloth top that can be
raised and lowered

73. Hatchback
The large rear door allows easy access
when hauling items

74. Station Wagon
Provides a large rear interior compartment

75. Sport-Utility Vehicle
Provides the comfort of a passenger car, the interior
space of a station wagon, and the durability of a
truck

76. Multipurpose Veh, Mini van, MUV
Has a higher roofline for more
headroom and cargo space

77. Multipurpose Veh, Mini van, MUV

78. Off - Roaders
• Higher ground clearance, low gears with higher torque, 4WD, Off
road(or Mud ) tyres, high travel suspension

79. Crash Testing

80. • Old Car vs Modern Car during Crash Test / Evolution of Car
Safety
• https://youtu.be/TikJC0x65X0