Apart from the type of fuel used, the engines are also divided on the basis of a lot of things, such as the presence of a spark plug in Petrol engines and a fuel injector in Diesel engines. We also know that lighter vehicles such as motorcycles, scooters, and cars typically use petrol in their engines whereas Diesel is used in much heavier machinery such as tractors, trucks, and buses. Thus, the types of fuel used also plays a major role in defining the major difference between Petrol and Diesel engines. More differences between these types of engines are listed in the tabular column below.
| Difference Between Petrol and Diesel Engine | |
| Diesel Engine | Petrol Engine |
| These engines work on the Diesel cycle | Works on the Otto cycle |
| The fuel is mixed with air inside the cylinder | Air and the fuel are mixed in a carburettor |
| Ignition is achieved with the help of the hot, compressed air. | Fuel is ignited with an electric spark |
| High compression ratio | Relatively low compression ratio |
| High power production | Relatively low amounts of power are produced in a Petrol engine |
| These engines work with fuels that have low volatilities | Highly volatile fuels are used in these internal combustion engines |
| Generally used in heavy vehicles such as trucks and buses | Used in light vehicles such as motorcycles and cars. |
| Relatively low fuel consumption | High fuel consumption. |
| High initial and maintenance costs | Comparatively low initial cost and maintenance cost |
