How does a spark plug work?

What is the purpose of a spark plug and how does it work?


Simply put, a spark plug is there to provide a spark to the engine cylinder during the combustion process. It does this through a high voltage ignition system, this system receives ignition voltage from the battery and runs it through a coil and onto the terminal of the spark plug, once there the electricity travels through the plug and to the bottom where it grounds out though the fine electrode tip and creates a quick spark. The spark is then used to ignite the fuel in the combustion chamber during the power stroke of the combustion process.

The spark is created in the power stroke, which is the third stage of a four stroke combustion cycle. First is the intake stroke, followed by compression, next is power and final is the exhaust stroke. Intake, compression, power, exhaust.



The process is pretty spectacular when you stop and think about it, what really blows my mind is the amount of spark/power that is created while we drive. If the engine is spinning at 2,500RPMs and it has 4 cylinders, that would be 10,000 sparks created per minute. Wild right? Now picture a Lamborghini, the engine is spinning at 8,000RPMs and it has 12 cylinders, that’s 96,000 sparks created in one minute, 1600 sparks per second!!



Good spark plugs are vital to proper engine performance, once our spark plugs start to lose efficiency it can take it’s toll on the overall performance of the engine. If you can’t remember the last time you had your spark plugs changed then I suggest you go get those bad boys replaced when you are next able to.



~As always, have fun and stay safe!!




  • Simon says:

    Very cool! I’ve been trying to get better at being hands on with my car because it’s hard to find affordable mechanics if you don’t know any and don’t know much about cars.

    I might not be able to fix my own car but at least knowing the ins and outs will help me not get ripped off when I go get it fixed.

    Very interesting how a spark plug works, a phenomenal example of engineering. Thanks for sharing!

    • GGrey says:

      Hey Simon, keep learning, things get easier the longer you try 🙂 It is an incredibly valuable skill to learn and have available to yourself.

      It’s always best to know what you are talking about when having your vehicle worked on, otherwise as you have said it is easy to get ripped off, an unfortunately true occurrence in the automotive industry.

      Take Care!

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