Diesel is a petroleum based fuel used in diesel engines. Diesel fuel helps diesel engines to operate more efficiently that gasoline powered engines however diesel fuel has become more expensive that gasoline in recent years. This increase in price is due to higher worldwide demand for diesel fuels and increased federal excise taxes. Diesel fuel is comprised of kerosene, oil, ether and an ignition improver.
Kerosene is the base fuel in diesel for road vehicles which is the major power-producing ingredient in the fuel. Because of a high calorific value, kerosene produces a high amount of energy from a low amount burned. Kerosene also has a low self-ignition temperature, which is the temperature at which it will self-ignite without an external flame. A high calorific value combined with a low self-ignition temperature make kerosene an important ingredient in road diesel as well as an effective fuel by itself for smaller machines. Diesel fuel usually features 42 percent kerosene.
Oil has three functions in diesel fuel. First, oil is a lubricating agent for the engine both during start up and under working conditions. Second, oil provides a gas seal for the engine by filling the microscopic spaces between its moving parts. Third, oil protects engine parts after the car is turned off because all of the other ingredients are burned off by the engine during use. It is important that the oil in diesel fuel has high film strength as well as the ability to maintain good viscosity so it can work both as a lubricator and a sealant, to protect the quality of engine parts. Diesel fuel is made up of 24 percent oil.
Ether has an extremely low self-ignition temperature which comes in useful during ignition. Though it is not an effective diesel fuel on it's own because of a low caloric value and inconsistent detonation, when ether is mixed with kerosene and oil, it reduces the overall requirements for ignition. Ether makes up 30 percent of a diesel fuel solution.
Diesel fuels feature various ignition improvers to further lower self-ignition temperature. Amyl Nitrate is the most popular ignition improver in North America. This ingredient is very flammable and dangerous on it's own but it stabilizes once it is mixed with the other components of diesel fuel. While ignition improvers increase the ability of a diesel engine to ignite, excessive amounts of this ingredient can cause erratic running and excessive overheating. Diesel fuels should be made up of 3 percent ignition improvers.