Compare Petrol Engine with Diesel Engine?

Basic cycle:

Petrol Engine works on Otto cycle whereas Diesel Engine works on diesel cycles.

Induction of fuel:

During the suction stroke in petrol engine, the air fuel mixture is sucked in the cylinder while in diesel engine only air is sucked into the cylinder during its suction stroke.

Compression Ratio:

In petrol engine the compression ratio in the range of 5:1 to 8:1 while in diesel engine it is in the range of 15:1 to 20:1.

Thermal efficiency:

For same compression ratio, the thermal efficiency of diesel engine is lower than that of petrol engine.

Ignition:

In petrol engine the charge (A/F mixture) is ignited by the spark plug after the compression of mixture while in diesel engine combustion of fuel due to its high temperature of compressed air.