Question

State the differences between the petrol engine and the diesel engine.

Answer 1

Hint: The petrol engine works on the Otto cycle and the diesel engine works on the diesel cycle and other differences are seen in their structure and uses of these engines. Apart from the fuel used they are different based on the spark plug presence and fuel injector presence in the engines.

Complete step by step solution:
In the diesel engine the fuel is mixed with the air inside the cylinder but in the case of the petrol engine, the air and the fuel are mixed in a carburetor. The ignition is achieved with the help of the hot and the compressed air in case of the diesel engine whereas the fuel is ignited with an electric spark in case of the petrol engine.

In the case of the diesel engine, the compression ratio is very high whereas in the case of the petrol engine the compression ratio is very low.
The value of the power production rate is quite higher in the case of the diesel engine and here in the case of the petrol engine the amount of power production is low.

The diesel engines work with fuel with low volatile nature and in the case of the petrol engines the high volatile fuels are used.

The diesel engines are used for the high or heavy vehicles and the petrol engines are used for the light motor vehicles such as bikes etc..

Diesel engines have relatively low fuel consumption while on the other side the petrol engines have high fuel consumption.

The maintenance costs of diesel engines are very high when we compare them with their competitors the petrol engines. The petrol engines have a very low initial cost and maintenance costs.

Note: We have identified and stated the important differences between the diesel and the petrol engines and the main difference is the working principle of the two engines and we have already seen the types of the cycles each engine works on. Other differences can be attributed to the structure and types and the uses of these engines.