The difference between petrol engine & diesel engine can be carried out with various parameters as follows
Sr. No. |
Petrol Engine (SI) |
Diesel Engine (CI) |
|
1. Suction stroke |
Petrol engine takes a mixture of air & petrol |
A diesel engine takes only air during suction
stroke |
|
2. Fuel Mixing |
The carburettor is used to mix air & petrol |
An injector or atomizer is used to inject fuel at end of the compression
stroke. |
|
3. Pressure at end of the compression stroke |
Pressure is about 10bar |
Pressure is about 35 bar |
|
4. Fuel Ignition |
Ignited with the help of Spark Plug |
Fuel-injected is sufficient to ignite the compressed air |
|
5. working Cycle |
Constant volume (Otto) cycle |
Constant Pressure (Diesel) cycle |
|
6. compression ratio CR |
The petrol engine has 6 to 12 |
The diesel engine has 10 to 24 |
|
7. Engine Starting |
Easy due to low CR |
Difficult due to high CR |
|
8. Running cost |
High due to the high cost of Petrol |
Low due to less cost of diesel |
|
9. Maintenance Cost |
Less |
High |
|
10. Engine Weight |
Lightweight |
More weight |
|
11. Thermal Efficiency |
About 24% |
About 40% |
|
12. Engine speed |
High |
Low |
|
13. Life span |
Less |
More |
|
14. Overhauling
requirement |
Frequent overhauling required |
Overhauling is done after a long time |
|
15. Maximum temp inside the cylinder |
The temperature reaches up to 1100 deg C |
The temperature reaches up to 2600 deg C |
|
16. Application |
Scooter, bikes, cars, etc |
Trucks, buses, tractors, etc |
