Diesel engines are everywhere; they are used in all sorts of vehicle platforms. From Volkswagen Jetta’s, to big eighteen wheel tractor trailer trucks. They provide more torque then a regular gasoline engine because of the long stroke of the piston. Most diesel engines make peak torque at very low rpm. Diesel engines do not have spark plugs. They develop combustion by heating up the air going into the cylinder, while the air is heated the fuel injector sprays into the bowl of the cylinder creating ignition. Diesel engines are also known as compression ignition engines. A typical gasoline engine is only thirty percent efficient, while a diesel engine can convert over forty five percent of its fuel energy into mechanical energy. The diesel engine started becoming popular in small vehicles because of the great fuel economy. They also became popular in light duty pickup trucks in the mid to late 80’s one of the most popular engines from that time is the Cummins twelve valve engine. Cummins is still one of the leading manufactures in diesel engines. While only using 6 cylinders the stroke of a Cummins engine is up to thirty percent longer then competitors.
Diesel engines are much more reliable than conventional gasoline engines because there is no spark for the ignition system. This makes diesels better in damp environments. Diesels can last up to twice as long as a gasoline engine because the parts used are much stronger, often made out of cast iron, and diesel fuel has much more lubricity than gasoline. The average diesel engine has a power to weight ratio that is less than a gasoline engine. This is because diesels operate at lower engine speeds, and because the components of a diesel are much heavier. Diesel components are usually heavier because of the high compression ratio. Some diesel engines can have a compression ratio as high as 24:1. The compression ratio is how much of the clearance volume will fit between bottom dead center and top