Like petrol engines, diesel engines are a type of internal combustion engine where fuel is burned inside the cylinders where power is produced. Air is pushed through the cylinders and forced to contract so much that it heats up. Fuel is then sprayed into the combustion chambers and it ignites, creating enough power to drive your car.
It is said that diesel engines are more efficient and there are several reasons for this.
First, they compress more and operate at higher temperatures; second, the lack of a spark plug allows for more fuel compression and in simple terms, therefore more energy; and thirdly, they need less fuel when working at lower power.
Without delving too much into the science behind diesel, it does have a higher energy density than petrol and is also a better lubricant so the engine runs with less friction.
Diesel engines are good for moving large loads at low speeds and have been commonly used in ship, truck, bus and locomotive engines. However, there have been huge developments and more and more car makers have produced diesel engines.
While there are plenty of positives for a diesel engine, there are also some negatives such as pollution. Although, many car brands are looking at ways to reduce the pollution levels.