What type of fuel is primarily used in a diesel engine?

Diesel engines are specifically designed to operate using diesel fuel, which is a heavier and more energy-dense fuel compared to the alternatives listed. Diesel fuel is derived from crude oil and has a higher lubricity, allowing it to better withstand the high compression ratios typical of diesel engines.

This fuel undergoes a different combustion process compared to gasoline, relying on compression ignition rather than spark ignition. The specific properties of diesel fuel, such as its cetane number, help in achieving efficient combustion, resulting in greater fuel efficiency and torque in diesel engines.

Gasoline, propane, and natural gas are fuels more commonly associated with other engine types, particularly gasoline engines. Using these fuels in a diesel engine would not only lead to poor performance but could also cause engine damage due to their different combustion characteristics and energy content. Thus, recognizing diesel fuel as the primary fuel for diesel engines is crucial for understanding their operation and maintenance.