All About Diesel Engines


What is a diesel engine?

A diesel engine is a type of internal combustion engine. An internal combustion engine is one where the fuel is burned inside the cylinders of the engine. The cylinders are the main parts of the engine that produce power for the vehicle and the fuel burns inside the cylinders to make this energy. The result is an engine that wastes less energy because the heat doesn’t have to flow from where it is produced into the cylinder. Everything happens in the same place.

How is a diesel engine different from a gasoline engine?

Both gasoline and diesel engines work by internal combustion, but in different ways. For gasoline engines, fuel and air is injected into the cylinders. A piston compresses the mixture, which makes it explosive and an electric spark from a spark plug sets the mixture on fire. This makes it explode, generating power to push the piston down the cylinder and, through the crankshaft and gears, turn the wheel.

Diesel engines are similar. Air is allowed into the cylinder and compressed by the piston. For diesel engines, the air is compressed more than in a gasoline engine. As a comparison, gasoline engines compress the fuel-air mixture up to a tenth of its original volume. In diesel engines, the air is compressed anything from 14 to 25 times. This compression creates heat. Once the air is compressed, fuel is sprayed into the cylinder by an electronic fuel-injection system. The compressed air is so hot that it instantly ignites and explodes the fuel without a spark plug. The explosion then pushes the piston out of the cylinder, producing the power the vehicle needs to drive. When the piston goes back into the cylinder, the gases are pushed out through an exhaust valve and the process is repeated.

How are diesel engines more efficient?

Diesel engines are up to twice as efficient as gasoline engines. The result is the ability to go further on the same amount of fuel. One reason is because diesel engines do not need spark plugs. This creates a simpler design that compresses the fuel more. Compressing the fuel more makes it burn more completely with the air in the cylinder, releasing more energy. Additionally, a gasoline engine that is not working at full power requires more fuel or less air to keep working. A diesel engine needs less fuel when they are working at lower power.

How is diesel fuel different?

This fuel is a lower-grade, less-refined product of petroleum that is made from heavier hydrocarbons. Down to a molecular level, diesel fuel carries more energy per gallon than gasoline because the molecules it’s made from have a higher energy density than gasoline. Diesel is also a better lubricant, meaning the engine runs with less friction.

Do you have a diesel engine that is in need of repair? Take your vehicle to the Auto Clinic of Stuart! We will help you keep your vehicle running in top condition!