What is the difference between the Otto and Diesel engine?

Otto engine Diesel engine

1. Works on Otto cycle 1. Works on diesel cycle.

2. Petrol use a fuel. 2. Diesel use as a fuel.

3. Heat addition at constant volume. 3. Heat addition at constant pressure.

4. Light in weight 4. Heavier in weight.

5. Low compression ratio 5. High compression ratio.

6. Low thermal efficiency 6. high thermal efficiency.