difference between diesel engine and petrol engine

1. Comparison between petrol
and diesel engine
by
Rampal Singh
B.E. (Mechanical), M.Tech (Production Engineering),
Thrice GATE Qualified

2. Petrol Engine Vs Diesel Engine
Petrol Engine
 Mixture of air fuel drawn
during suction
 Carburettor used for fuel
injection
 Compression ratio 6-10
 Maximum pressure about
10 bar
Diesel Engine
 Only fresh air is drawn
during suction
 Fuel injectors are used
 Compression ratio 15-25
 Maximum pressure about
35 bar

3. Petrol Engine Vs Diesel Engine
Petrol Engine
 Works on otto cycle
 Light in weight and cheap
 Operates at high speed
 Occupies less space
 Thermal efficiency is
around 25%
 Used in scooter, motor
cycle
Diesel Engine
 Works on diesel cycle
 Heavy and costly
 Operates at low speed
 Occupies more space
 Thermal efficiency around
40%
 Used in bus, trucks,earth
moving machines and other
heavy duty machines