What type of ignition system does a diesel engine use to ignite fuel?

What type of ignition system does a diesel engine use to ignite fuel?

• A. Spark
• B. Compression
• C. Electric glow
• D. Magnetic ignition

Answer: (B)

Diesel engines ignite fuel through compression. When air is squashed to a very high pressure inside the cylinder, its temperature rises dramatically. Fuel is then injected into this hot, high-pressure air and auto-ignites without any spark. This is the defining difference from spark-ignition engines, which rely on a spark plug to provide the ignition energy for gasoline. Glow plugs may be used to help starting in cold conditions by warming the chamber, but they do not ignite the fuel themselves. Magnetic ignition isn’t part of diesel systems.

Diesel engines ignite fuel through compression. When air is squashed to a very high pressure inside the cylinder, its temperature rises dramatically. Fuel is then injected into this hot, high-pressure air and auto-ignites without any spark. This is the defining difference from spark-ignition engines, which rely on a spark plug to provide the ignition energy for gasoline. Glow plugs may be used to help starting in cold conditions by warming the chamber, but they do not ignite the fuel themselves. Magnetic ignition isn’t part of diesel systems.