4 Types of Spark Plugs (Copper vs Iridium vs Platinum vs Double Platinum)

Choosing the correct spark plug for your engine can be difficult, considering all the different types. Here's everything you need to know about different types of spark plugs to choose the correct one.

Types Of Spark Plugs

What is a spark plug? How do they work? Why do they vary in cost?

These are just a few of the questions that we’ll aim to answer for you in this article. 

In this article, we will go through the different types of spark plugs on the market and which one to choose for your car engine. We will also look at some basic information about spark plugs. Let’s begin!

Types of Spark Plugs

The four main types of spark plugs are the copper spark plug, iridium spark plug, platinum spark plug, and double-platinum spark plug. Each spark plug type has its own advantages and disadvantages.

We’ve crafted a handy list for you, including the difference in materials used and the differences in efficiency and cost. Here’s a more detailed list of the different types of spark plugs:

1. Copper Spark Plugs

Copper Spark Plugs

Copper spark plugs are the common name for most basic spark plugs that you can get hold of. However, this term is quite incorrect, as standard material plugs do not have electrodes made from copper because copper is a very soft material that will melt fast.

A “Copper Spark plug” or standard spark plug uses a nickel-alloy that may include a small copper core. Actually, all types of spark plugs include a copper core inside of them.

The body of these copper spark plugs is physically the largest out of all the ones listed here. This is due to how inefficient they are compared to a larger voltage to generate a spark.

These plugs are best suited to older vehicles that don’t have lots of accessories fitted to them and have a basic performing engine. 

Plugs such as these tend to be fairly cheap to purchase and usually won’t cause any problems as long as they’re changed at regular service intervals – depending on what the manufacturer recommends. 

2. Iridium Spark Plugs

Iridium Spark Plug

These are some of the top tier plugs that you can get your hands on in the standard consumer market. Being made from Iridium, they will last much longer than standard copper plugs and platinum plugs. 

This is mainly because of how durable iridium is as a metal. Not only is it incredibly strong and durable, but it’s also a great conductor. This means that the plug’s body can be a lot smaller as it doesn’t require as much electricity to generate a spark, which makes them much more efficient also. 

You probably think that iridium sounds pretty awesome – and it is, which is why it comes with a heavy price tag. 

Although these plugs are quite expensive, however, they’ll usually last around 50,000 miles which means they don’t require changing very often at all. 

Iridium plugs are often fitted to newer vehicles running higher performance engines; if this is the case for you, we recommend replacing your spark plugs like for like. 

3. Platinum Spark Plugs

Platinum Spark Plug

Platinum spark plugs are fairly similar to copper spark plugs in their makeup, except they feature a platinum tip design that is welded to the end of the center electrode, making it much more durable and longer-lasting than the basic nickel alloy tip featured on a copper spark plug. 

Platinum spark plugs can usually last around 100,000 miles due to their better durability and improved ability to handle higher temperatures.

Whilst these plugs are neither the most efficient nor the most durable plugs on the market when compared with iridium spark plugs, they do come at a lower cost. This is what makes them a great middle ground for your vehicle, provided your manufacturer specifies them. 

4. Double Platinum Spark Plugs

Double Platinum Spark Plugs

Again, these double platinum spark plugs are similar in design to both a copper and a single platinum spark plug, except they feature a laser welded platinum inlay.

This double-platinum design on both the electrode and the inlay makes these plugs even more efficient and durable—all for a lower price than Iridium plugs. 

These are a great option if you would like an upgrade from single platinum spark plugs, but don’t want to pay out for iridium plugs. 

RELATED: 6 Causes of Oil on Spark Plugs

What is a Spark Plug?

Spark Plug Function

So, what exactly is a spark plug? A spark plug is used to ignite your fuel as it gets injected into your engine’s combustion chamber. This will only apply to petrol engines as other fuels are ignited by different methods. Your engine will usually have one spark plug per cylinder bore, which gets an electrical feed either directly from a coil pack or indirectly via HT (high tension) leads. 

In both cases, a high amount of voltage is generated by your vehicle’s coil pack and then sent through to your spark plugs. This electrical energy that gets transmitted will then jump the gap between your plug’s center electrode and it’s ground electrode. As the electrical charge jumps the gap, it gives off a visible spark (hence the name spark plug), and this is the spark that ignites your fuel causing a miniature explosion which is what keeps your pistons moving and your engine turning. 

What makes the spark plug such a great component is it’s simple design. Whilst it remains one of the most vital parts of your engine and does a vast amount of work, they still remain beautifully simple in their method of operation. 

Whilst nearly all spark plugs remain the same in how they operate, they do vary in their efficiency, depending on the material they’re made from. 

RELATED: How Long Do Spark Plugs Last?


Hopefully, this guide has given you an insight into the main differences between the 4 most common spark plugs on the market. As with most things, it’s good to balance spending money up front with potential repairs that need carrying out in the future. 

Spark plugs are a vital component in your engine and won’t run without them. They’ll keep your engine running not only efficiently but also smoothly. This is why it’s so important to spend the time and money on proper maintenance. 

Do you want to know which is the best spark plugs to choose? Check out our other guide: best spark plugs.

Please feel free to refer back to this guide whenever you need to for a help hand.


Bosch Spark Plugs

NGK Spark Plugs

Magnus Sellén
Written by:

Magnus is the owner and main author of Mechanicbase. He has been working as a car mechanic for over 10 years, and the majority of them specialized in advanced car diagnostics and troubleshooting. Certified Automotive Diagnostic Technician.

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