DIESEL 101: How Do Diesel Engines Work?

image of truck diesel engine  - Enginetech Machining

Whether you’ve never operated a diesel engine or you use one every day, you might not know how a diesel-powered system works. While most of the components and processes are extremely similar to a traditional, gasoline-fueled internal combustion engine, there are some key differences that set diesel apart. So take a seat and pull out your notebooks, EngineTech’s introductory course on the diesel engine is about to begin.


An internal combustion engine is a contained system where compressed fuel-and-air mixture is ignited, often by electrical means. This system then harnesses the energy produced by the explosive result and converts it into kinetic energy, which powers your vehicle or equipment. The internal combustion system was invented by Étienne Lenoir and mastered by Nikolaus Otto and other designers. All modern gasoline engines are internal combustion engines; they commonly use sparkplugs for ignition. Diesel engines are also internal combustion engines, but they employ a different form of ignition.


Compressing any vaporized fuel will create heat– in diesel engines, the compression is so efficient that the fuel mixture ignites without the need for a spark plug. The simpler, more economical system is a major advantage of diesel engines over their gasoline counterparts. This form of internal combustion was invented by Rudolf Diesel and mastered by modern engineers; now it is widely used for consumer and industrial use alike.


  • Diesel fuel contains approximately 15% raw energy compared to gasoline
  • Cold or humid weather can hamper diesel ignition– glow plugs are used to warm an engine’s cylinders to prevent this issue
  • Diesel engines’ higher torque means more power at lower RPM, good for towing and other heavy-duty uses
  • More robust components and less complex design increase the reliability and long-term durability of diesel engines
  • Biodiesel is one of the most ecologically-friendly fuels available on the market

Do you still want to know more about diesel power? Read EngineTech’s other blogs that cover the origins, advantages, features and functions of the diesel engine. Contact or visit EngineTech today for any of your diesel power and performance needs. Our expert staff can guide you to the right solution for your situation.