Our Guide to Different Types of Spark Plugs for the Future Automotive Technician

Auto mechanic holds an spark plug
Because they’re responsible for making an ignition system work, spark plugs are one of the most important parts you’ll find in a gas-powered engine. When firing up a car, gasoline gets mixed with air inside of the cylinder head. Spark plugs create miniature lightning bolts that ignite this mixture in order to push pistons down and complete the ignition process. Diesel engines, on the other hand, run at a much higher compression rate, so they can create combustion and ignite without the help of a spark plug.

Spark plugs are designed with a central electrode that’s covered by a layer of porcelain insulation. The central electrode is connected by a heavily insulated wire to the output terminal of a vehicle’s ignition coil. Some expensive spark plugs advertise a “fine wire” core. This means they have an inner central wire with added metals that conduct electricity better, and they usually last longer.

If you’re planning to become a mechanic, read on to learn about the different types of spark plugs you might handle throughout your future career.

An Automotive Technician can Use Copper Spark Plugs in Most Engines

Copper spark plugs have a solid copper core, and are typically the most affordable type because copper tends to erode away over time. Copper, however, is able to conduct electricity better than any other type of material used on spark plug tips. Because of this, copper-tipped plugs deliver more power in performance driving without overheating, which reduces engine power and shortens spark plug life.

Copper also produces the best spark under the adverse conditions generated by turbochargers or higher compression ratios. As a result, you might notice during your auto mechanic apprenticeship that manufacturers of these types of engines typically use copper plugs as original equipment. Depending on a variety of factors, copper spark plugs usually only need to be changed after 32,000 to 64,000 km. Experts say that copper spark plugs are the best choice for engines that use natural gas.

An Automotive Technician Should Use Platinum Spark Plugs for More Durability

Platinum-tipped spark plugs usually cost more since platinum is a rarer metal than copper. Compared to copper, however, platinum conducts less of an electric current and might also become overheated in performance driving conditions. The main reason that platinum spark plugs are popular is because they last much longer under normal driving conditions. Platinum also doesn’t erode away like copper does over time, which means that it won’t cause any delays in ignition or cause check engine lights to pop up.

You won’t have to change out sets of platinum spark plugs very often once you become an automotive technician—they typically last twice as long as copper spark plugs and can even last up to 250,000 km.

Choose Iridium Spark Plugs for Top-of-the-Line Performance

Iridium Spark Plugs not only offer better power and more reliable combustion, but they also typically last about 25 per cent longer than comparable platinum-tipped plugs. Iridium spark plugs are the most expensive not only because iridium is harder than platinum, but also because these plugs are built with a “fine-wire” core. This allows them to conduct energy much better than other spark plugs, which leads to a smoother-running engine and fewer ignition issues.

Iridium spark plugs are high quality and don't need to be changed out often
Iridium spark plugs are high quality and don’t need to be changed out often

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