Automobile Engineering (UG Level): Full
Detailed Course Notes
1. Introduction to Automobiles
Automobile engineering is the branch of engineering that explores the design,
manufacturing, operation, and maintenance of vehicles such as cars, trucks, buses, and
motorcycles. The modern automobile is a highly complex system consisting of thousands of
mechanical, electrical, electronic, and software components working together to achieve
safe and efficient transportation.
History: The evolution of automobiles began in the late 19th century, with Karl Benz and
Henry Ford pioneering early designs. Modern vehicles include both IC (internal
combustion) and electric/hybrid models.
Vehicle Classification: Cars may be classified by size (compact, sedan, SUV), by propulsion
(internal combustion, hybrid/electric), or purpose (passenger, goods, off-road). The main
parts of any automobile are the chassis, engine, transmission, suspension, steering, brakes,
electrical/electronic systems, and body.
2. Automotive Engines
An automobile engine (powerplant) is the heart of the vehicle, converting fuel energy into
mechanical energy to drive the wheels.
2.1 Types:
- SI Engines (Spark Ignition, petrol): Fuel is mixed with air, compressed, and ignited by a
spark plug.
- CI Engines (Compression Ignition, diesel): Only air is compressed, fuel is injected and
ignites due to heat of compression.
- Hybrid and Electric Powertrains: Use batteries, electric motors, and control systems.
2.2 Main Parts:
- Cylinder block and head, piston, connecting rod, crankshaft, camshaft, valves, timing
gears/belt, ignition/fuel injection system.
2.3 Engine Cycles:
- Four-stroke (intake, compression, power, exhaust).
- Key engine parameters: displacement, compression ratio, power, torque, efficiency.
2.4 Supporting Systems:
- Lubrication: Reduces friction. Wet/dry sump, oil pumps, filters.
- Cooling: Keeps engine within safe temperature. Water/air cooled, radiators, pumps.
- Fuel supply: Carburetors (older), fuel injection (modern).
2.5 Emissions:
- Types (CO, NOx, HC, particulates). Electronic emission controls, catalytic converters, EGR.
3. Transmission Systems
Transmissions transmit engine power to the wheels and let drivers change speed/torque
ratio as needed.
3.1 Clutch: Enables smooth engagement/disengagement of engine and transmission
(single/multiplate, centrifugal, hydraulic).
3.2 Gearbox: Manual (sliding mesh, constant mesh, synchromesh) and automatic (planetary,
CVT, DCT).
3.3 Differential: Allows wheels to rotate at different speeds during turning.
3.4 Propeller Shaft and Final Drive: Transmit torque to the driven wheels.
4. Chassis, Suspension, and Steering
4.1 Chassis: The main frame structure supporting engine, drivetrain, and body. Ladder,
monocoque/unibody, spaceframe types.
4.2 Suspension: Spring and shock absorber systems to isolate vehicle from road
irregularities. Includes leaf spring, coil spring, torsion bar, MacPherson strut, multilink, air
suspension.
Suspension geometry: Caster, camber, toe-in/out.
4.3 Steering: Manual and power-assisted systems. Recirculating ball, rack and pinion,
electronic power steering.
Advanced: EPS (Electronic Power Steering), Steer-by-wire.
5. Brakes and Control Systems
5.1 Brakes: Drum, disc brakes; components (pads, rotors, calipers);
mechanical/hydraulic/pneumatic actuation.
5.2 Advanced Systems: ABS (prevents wheel lock-up), EBD (Electronic Brakeforce
Distribution), ESC (Electronic Stability Control).
5.3 Brake testing and safety standards.
6. Electrical and Electronic Systems
6.1 Battery: Lead-acid, lithium-ion; function, maintenance, safety.
6.2 Starter and Charging: Starter motor, alternator, starter relay.
6.3 Ignition: Conventional (coil, contact breaker), Electronic/Electronic Ignition (EI, CDI,
Direct ignition).
6.4 Lighting/Signalling: Headlights, taillights, indicators, wiring.
6.5 Electronics: Sensors, actuators, ECUs (Electronic Control Units), OBD-II basics.
6.6 Modern in-vehicle networks: CAN, LIN, FlexRay.
7. Automotive Body Engineering
7.1 Body Types: Hatchback, sedan, SUV, coupe, convertible.
7.2 Construction: Monocoque vs chassis-based, crash safety (crumple zones, reinforcement
beams, airbags).
7.3 Aerodynamics: Drag reduction, airflow, spoilers, coefficient of drag.
7.4 Materials: Steel, aluminum, composites, plastics. Paint and surface protection.
8. Automotive Maintenance and Servicing
8.1 Preventive Maintenance: Service schedule (oil, filters, brakes, coolant, tyre checks).
8.2 Diagnostics: Visual inspection, use of scanners, basic troubleshooting charts.
8.3 Workshop Practices: Safety, use of special tools, torque specs, common adjustments and
repairs.
9. Modern Trends in Automobiles
9.1 Electric and Hybrid Vehicles: Architecture, motors, batteries, regen braking, control
systems, charging standards.
9.2 Advanced Safety and Driving Aids: ADAS—Lane Keep Assist, Autonomous Emergency
Braking, Adaptive Cruise Control, airbags, automatic parking.
9.3 Infotainment and Connectivity: Touchscreens, telematics, car-to-x communication, over-
the-air updates.
10. Laboratory and Practical Work
Practical work includes engine disassembly/assembly, brake strip/adjustment, electrical
wiring harness layout, use of diagnostic scan tools, and suspension/steering service checks.
Laboratory exercises cover performance and emissions testing, inspection, and field
reports.
References and Textbooks
• Automobile Engineering by Kirpal Singh
• A Textbook of Automobile Engineering by R.K. Rajput
• Basic Automobile Engineering (Tamil Nadu Board)
• Automobile Electrical and Electronic Systems by Tom Denton
• NPTEL Online Resources & Video Lectures
• OEM manufacturer manuals
