The main difference between petrol and a diesel engine is the way they work and Use their fuels. What happens in a petrol engine is that at first the fuel is mixed with air, then pistons compresses it and after compression it is ignited by spark plugs. On the other hand in a diesel Engine Air is first compressed and then mixed with fuel, the compressed gasses increase the temperature of the chamber manifolds and this in turns ignites the fuel.
A petrol Engine is also called a gasoline engine. When air and fuel are compressed together in a chamber in the petrol engine, there is increased risk of auto explosion so the ratio of their compression must be kept precise. When it comes to speed they are really fast and efficient. Their pistons are short and they cause the production of spark from spark plug rapidly, makes it to start easily and immediately..
A diesel engine uses diesel as fuel and it does not need a spark plug. They are self ignited due to high temperature available in the chamber which is created by highly compressed gasses.
- A diesel engine uses less fuel because the temperature in the ignition chamber is really high due to compressed gasses and it does not need to burn too much fuel to increase the temperature to a certain limit.
- The pistons of petrol engine are smaller than the pistons of the diesel engine and this helps to give the petrol engine more speed and efficiency than diesel engine.
- A diesel engine has long age then a petrol engine. The reason is usage of strong machine parts and the presence of lubrication to these parts which is provided naturally by the fuel used.
- There are no igniting sparks for diesel engine but a petrol engine is started by the sparks from spark plug.
- The efficiency for a petrol engine is 30 percent but for a diesel engine is 45 percent.. it means that a petrol engine can utilize 30 percent of its fuel power while a diesel engine can utilize 45 percent of fuel power.