The main difference is that the diesel engine cylinder pressure

The main difference is that the diesel engine cylinder pressure in the mixed gas is fired, not lit. The diesel engine when the air entering the cylinder, compressed air in the cylinder to the end, the temperature at 500-700 ℃, pressure 40-50 atm. When the piston approaches top dead center, high-pressure pump on the engine petrol dispenser pump at high pressure to the cylinder injection diesel, diesel oil to form a fine grain, mixed with air high pressure high temperature combustion diesel hybrid gas itself, violent expansion, generating power, push the piston down acting . At this point the temperature 1900-2000 ℃, pressure up to 60-100 atmospheres, great power, therefore, widely used in diesel engines on large diesel vehicles.