What Are Spark Plugs And Why Are They Important?

One of the most common causes of reduced engine performance is a bad spark plug, To help you better understand spark plugs and how they work, here's a write-up on what spark plugs are and why they're important. 

Spark plug illustration

A typical spark plug

What Are Spark Plugs And What Do They Look Like?

A spark plug is a small electrical device that protrudes into the combustion chamber. One spark plug is provided for each combustion chamber in an engine. A typical spark plug is a few inches long, and it comes in a tubular shape. The top of the spark plug is connected to the ignition coil. The bottom end of the spark plug has a hook-shaped ground electrode.

spark plug electrode

The hook-shaped ground electrode

What Purpose Do Spark Plugs Serve?

Spark plugs exist to ignite the air/fuel mixture in your engine. They draw the energy from the ignition coil and then shoot mini lightning bolts that ignite the air/fuel mixture. When the air/fuel mixture is ignited, it creates a tiny explosion that helps power the engine.

How Do Spark Plugs Ignite The Engine?

When you turn the ignition switch on, the engine starts running almost immediately. There's actually a whole process that leads to the spark plugs igniting the fuel mixture. As soon as you turn the key, the following sequence of events is kicked into motion and is complete in a second or two:

  • The power from the battery travels to the ignition coil.
  • The ignition coil converts the 12v power into 30,000 volts required for spark plugs to work correctly.
  • The electronic ignition system takes the power supply and then distributes the volts to the spark plugs in order. (Basically, the spark plugs have to fire in a certain order to optimize the engine's performance).
  • The spark plugs ignite the compressed air/fuel mixture inside the combustion chambers, creating tiny explosions that power the engine.

Fun fact: Know that noise engines make? It's actually a bunch of tiny explosions happening at the same time!

This illustrates how important spark plugs are. Without functioning spark plugs, your engine can't run properly.

How Often Do Spark Plugs Need To Be Replaced?

Since spark plugs never stop working as long as the engine is on, they eventually wear out. It's common for spark plugs to go bad after about 30,000 miles. When you notice the signs of a bad spark plug, you would need to replace it as soon as possible. On our website, you'll find genuine OEM Mazda spark plugs at wholesale pricing. You would be hard-pressed to find a better deal than that.