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Automotive

What are Spark Plugs and How Do They Work?


While it’s true that every component in your car is important to its function, there are some that are more critical than others. When it comes to smooth running and reliability, sparkplugs are right up there with your fuel, oil, and the internal engine components. Spark plugs control ignition within the combustion chamber, and without them, your car simply could not run.

If you’re wanting to understand more about how your car works, then spark plugs are a great place to start.

From the Tiniest Spark to Power Under Your Feet

Just as the name implies, spark plugs create a small electrical charge within your engine. Plugs are designed in a way that the electricity arcs from a metal pin onto a larger metal element, allowing the fuel to combust within your engine. Everything happens in a split second, but is crucial to the performance of your car. The quality of your spark plugs will determine how much fuel your car uses, how efficient each cylinder is running, and how smooth your engine is able to idle and accelerate. A faulty plug could mean misfiring on a cylinder, or a dead plug could mean the complete loss of one of your cylinders. This could cause symptoms ranging from areduction in power, to a dead engine in the most extreme scenarios.

While spark plugs perform a seemingly basic task, they actually have quite a difficult job. They need to be designed in a way that they can keep performing for tens of thousands of miles, and they also need to be able to withstand the extreme heat and pressure that is created within your engine. With poor quality spark plugs, your car is simply not going to perform to its full potential, which is why it’s so important that you use the highest quality plugs that are available for your make and model.

Three Types of Spark Plugs

Unlike many other automotive components, spark plugs for most passenger and commercial vehicles follow standardized sizing and design. The main difference between plugs is the metal that is used on the center electrode. The three metals in order of cost and durability are copper, platinum, and iridium.

Copper sparkplugs are the most common type, and are used in economy and standard vehicles. These are cost effective to manufacture, and are the most inexpensive plugs that you can buy. Copper plugs use the widest diameter electrode where the spark is produced, which means that they use the most voltage out of the three plug types. Due to their design and material, they also wear out the fastest. Most manufacturers recommend that copper spark plugs are changed every 30,000 miles, although in some conditions they could retain their performance for twice that time, depending on your engine power and driving style. If you own a classic car that was produced before 1980, then copper may be the only plug type suited to your car, so check with a trusted mechanic before you consider changing to another material.

Platinum is a harder material than copper, and is used in modern cars and in some older performance cars. These plugs have a smaller disc on the electrode, making them more efficient. They also create a more powerful ignition spark, which can help to keep the tip of the plug clean, which in turn makes the entire plug more durable. Platinum plugs can sometimes be rated for up to 100,000 miles of operation, which is a significant jump when compared to copper plugs.

Moving up once more, we have iridium plugs. Harder than both copper and platinum, these are the most efficient and durable plugs that are available. These plugs are produced only by mainstream performance orientated manufacturers like Denso, NGK, and Bosch, and are often rated for up to 125,000 miles of operation. These plugs feature a center electrode that is even smaller than those on platinum plugs, sometimes being as thin as 0.4mm. Because of the tip design, efficiency is increased, which allows for the smoothest idling and acceleration from high performance engines. Some modern engines have been designed exclusively for the use of iridium plugs, so many recently manufactured cars and high performance exotics will require these plugs.

Top Spark Plug Brands

Many vehicle manufacturers will sell factory original plugs in branded packaging, however, these often come from OEM companies that specialize in the design and production of spark plugs. The previously mentioned brands of Denso, NGK, and Bosch, are all considered top brands, and are found in some of the world’s best high performance vehicles. Companies like Ford, BMW, Porsche, and Ferrari, all rely on spark plugs produced by these companies. Another major manufacturer is ACDelco, which produces plugs in all materials and designs. If you want to know just how good the plugs from these companies are, then consider that NGK makes sparkplugs used in both Indy Car and Formula 1, so they’ll be more than enough for your luxury or high performance road car.

Can You Replace Your Own Spark Plugs?

It’s possible to replace your spark plugs at home, but you’ll need to make sure you have the right tools, and it can be risky to make changes if you don’t have prior experience or training. You’ll need a torque wrench with a special attachment for reaching inside the spark plug chamber, and you’ll need to be extremely careful not to damage the thread when removing or adding spark plugs. You may also require specialist fluids that reduce the torque where the spark plug sits, and there are also fluids for preventing damage or fusing of the spark plug to the engine material.

Although it might seem that spark plugs are a simple screw-in engine component, the reality is that any small mistake could be costly and difficult to repair. Because of this, it’s recommended you visit a trusted service center if you’re not already comfortable with replacing your own plugs.

With this information, you now know more about one of the most important components in your vehicle. If your model is compatible with platinum or iridium plugs, then it is definitely worthwhile to upgrade, and any cost increase will easily be offset by improved fuel efficiency and plug durability.