Diesel engines and gasoline engines are both internal combustion engines. They both depend on a spark and miniature explosion inside the engine to create the power that is necessary for the engine to work and move the car along. However, there are some differences in how the engine manages to do that,
The way that the gasoline engine creates the necessary spark is that a fine mist of gasoline is mixed with air. That mixture is injected into the cylinder as the piston comes up and starts to compress the area. That fuel/air mix meets the spark from the spark plug and combusts. The resulting combustion causes the cylinder to go back down, generating the necessary power. The cycle is being repeated in all the engine's cylinders and keeps cycling while the engine is running.
One benefit of a gasoline engine is that the fuel doesn't gel like diesel fuel can so a gasoline engine can be used in much colder temperatures than a diesel engine can.
The diesel engine functions in a similar fashion as the gasoline engine. One difference between the two is that the diesel engine doesn't have a spark plug to initiate that combustion cycle. Instead, the piston compresses the air in the cylinder. Compression causes the air to heat up. When the piston is as high as possible and the air is as compressed as possible, a mist of diesel fuel is sprayed into the cylinder. It meets that heated and compressed air and causes a mini-explosion, driving the cylinder back down, causing the power stroke of the engine. This method is called direct injection since the fuel is directed directly into the cylinder.
Some diesel engines come with something called a glow plug. The reason that a diesel engine needs to have a glow plug is because when the temperature is cold, it can make it hard for the engine to start. The air might not get hot enough for the compression necessary to cause the diesel to explode. Also, the diesel may have thickened or gelled. The glow plug preheats the air so that the right temperature can be met in the cylinder and can also help to warm up the diesel, making it flow easier again.
Diesel engines and gas engines are both internal combustion engines. They just get the combustion part of the power they use to create the power of the car in different ways. For further assistance, contact local professionals, such as those from Ferrell Fuel Co Inc.