Difference Between Petrol Engine and Diesel Engine

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Difference Between Petrol Engine and Diesel Engine:

Petrol Engine: Petrol or Spark Ignition Engines In petrol or spark ignition engines, the carburetor creates a mixture of petrol and air in specific proportions and the engine cylinder receives and compresses it. But the pressure of the compressed mixture is not as high as in a diesel engine. An electric spark is generated in the compressed mixture using a spark plug.The spark ignites the mixture of petrol and air.

Diesel Engine: Diesel Engine or Compression or Ignition Engine In a diesel engine, the air inside the cylinder is compressed to very high pressure (40-45 kg/sq cm).The high pressure causes the compressed air to heat up to almost red hot or 600°C. In this condition, diesel fuel is injected into the vaporizer at a higher pressure.The fuel is ignited instantly by the high heat of the compressed air.

Detailed difference between Diesel Engine and Petrol Engine:

Detailed differences between Diesel and Petrol Engines are given below:-

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Serial No	Diesel Engine	petrol engine
1	The cylinder only takes air and does not require a carburetor.	The cylinder receives a mixture of fuel (petrol) and air. A carburetor creates a mixture of petrol and air.
2	Fuel is injected through injectors to ignite compressed air.	The compressed mixture is ignited by an electric spark plug.
3	Diesel is used as fuel.	Petrol is used as fuel.
4	The ratio of air to fuel is not fixed.	The ratio of air to fuel is usually constant and is 15:1.
5	Combustion does not require electricity or electrical sparking.	Combustion requires electricity or electrical sparking.
6	Compression ratio from 14:1 to 20:1.	Compression ratio from 4:1 to 8:1.
7	Compression pressure 40 to 45 kg/sq cm.	Compression pressure 7 to 10 kgsqcm.
8	The heat of contraction is about 600°C (red hot).	The heat of contraction is 200°C to 300°C.
9	Thermal efficiency is 32-38%.	Thermal efficiency 25-32%.
10	Ignition pressure 50 to 60 kg/sq cm.	The ignition pressure is about 20 kg/sq cm.
11	This engine runs on a diesel cycle.	This engine runs on an auto cycle.
12	This is a constant pressure cycle.	This is a fixed volume cycle.
13	Only air enters the cylinder during suction.	Air and fuel mixture enter the cylinder during suction.
14	Diesel is sprayed by a high-pressure pump injector at the end of the compression stroke to affect combustion.	Battery requires an ignition coil, CB point, distributor and spark plug, etc to perform combustion.
15	High-pressure pumps and injectors are essential for the fuel system.	AC pump and carburetor are very important for fuel systems.
16	This engine uses relatively low-quality oil.	High-quality oil is used in this engine.
17	This engine has more performance.	This engine has low performance.
18	This engine has a short lifespan.	This engine has a long life.
19	Relatively low RPM is available.	Maximum RPM is available.
20	Heavier in weight, for parity.	Lighter in weight, for equal strength.