Spark plugs

Copper & Iridium VS Platinum Spark Plugs

Daniel McDonald
Daniel McDonald8 min read
Copper & Iridium VS Platinum Spark Plugs

Contrary to popular belief, not all spark plugs are the same. While the primary purpose of each spark plug is the same, to generate electric current and ignite the fuel and compressed air, some spark plugs are more effective and achieve better results than others.

Continue reading to learn the differences between different spark plug materials.

What Is A Spark Plug?

While they may be one of the minor car components, the spark plug’s role is essential. Spark plugs are the small mechanical components found on top of each cylinder. Their role in the combustion process is crucial.

Spark plugs are used to ignite the engine fuel while it gets inserted into the combustion chamber. These tiny mechanical components give your engine the spark it needs to begin with the combustion cycle. The plugs ignite the air/fuel combination by creating an electricity curve between two electrodes.

Essentially, the spark plugs send high-voltage electricity at one end to trigger the spark at the other end. Once the spark is heated, the air/fuel combination will fire inside the chamber and create combustion. Once the spark happens, the car is forced to start. Therefore, they were called spark plugs.

Spark plugs ensure the engine ignition and its smooth running. They are found in each gas-fueled engine. You can find them in many distinct sizes, but the hex size is essential. The hex size determines whether the plug will fit in the socket.

Also, to ensure maximum performance, you must consider the gap between electrodes.    

Spark Plugs: Formation And Metal Purpose

The size of a spark plug gets smaller and smaller each day. The practice of producing tiny spark plugs is so they can fit perfectly and have a lot of flexibility in the combustion chamber. Also, since they hold enormous energy, they must be straightforward to operate.

Most spark plugs have two electrodes, one at the center and one at the skirt. Copper forms the central one because it has excellent properties and transmits heat faster than other materials. Since the copper is so soft, the copper spark plugs need a nickel-alloy cover.

The second electrode is also made out of copper, called the Ground electrode. To enhance the performance, the electrode has an iridium or platinum tip. The space between the two electrodes is called the electrode gap, which gets smaller with time. The necessity for smaller gaps is evident – smaller gaps mean less voltage for generating electricity flow.

The purpose of the metal in spark plugs is obvious – the metal channels the energy to generate a spark that will go across the gap. The spark generation is the crucial point where the combustion process starts. Therefore, the metal serves as a conductor.

Some metals are better conductors than others simply because they do not overheat quickly. Continue to read to find out all the advantages and disadvantages of different metal materials in spark plugs.  

Pros And Cons: Copper Spark Plugs

The copper spark plugs are the most basic ones. A copper spark plug is made primarily out of solid copper. However, other materials are also used since copper is very soft.

Copper spark plugs have a central electrode that contains a nickel alloy top. The nickel-alloy central electrode is the largest, so the copper spark plug needs much more energy to initiate electric power.

Copper spark plugs are compatible with older vehicles that work on a basic engine and don’t contain a lot of accessories. Spark plugs made of copper are more inefficient and cheaper than others. However, they may work fine if changed regularly according to the manufacturer’s manual.

On the pro side, copper spark plugs are best for vehicles produced before 1980ties that have a basic ignition system. Also, copper spark plugs are the cheapest. Since copper is a superconductor compared to iridium or platinum, if replaced regularly, the copper spark plug won’t create any inconveniences.

On the negative side, they have short longevity, are inefficient, and need replacement every 20,000 miles.

Pros And Cons: Iridium Spark Plugs

Iridium spark plugs can handle heat better than copper and platinum plugs. They have the most extended lifespan; iridium is at least six times more resilient than platinum. While an iridium spark plug might be a bit pricier, it is worth the money.

The central electrode of the iridium spark plug is tiny, which means it needs a lot less voltage than the copper spark plug. For this exact reason, manufacturers are recommending the usage of iridium plugs.

Aside from the more petite body, the iridium spark plug has a higher melting point. If you started using your vehicle with iridium spark plugs, you shouldn’t downgrade to copper or platinum. Downgrading will decrease the vehicle’s performance.

There are many advantages to using an iridium spark plug:

  1. They have smaller electrodes, which means they need less voltage;

  2. They are better suited for new vehicles that have a high-performance engine;

  3. They last at least 60,000; on some cars, they go up to 120,000 miles until they need replacing.

On the flip side, the iridium spark plug is the classiest spark plug, with a price range between 8 and 15 dollars. Also, once you start using iridium spark plugs, you shouldn’t downgrade to copper and platinum spark plug.

Pros And Cons: Single Platinum Spark Plugs

The platinum spark plugs are not the most efficient, similar to the copper plugs. However, their platinum electrodes double the copper spark plugs’ melting point. Therefore, they handle heat better and outlast the copper spark plugs.

What is different about the single platinum spark plugs is that they have a disc made of platinum on the central electrode. So, the platinum spark plug generates more heat; thus, the debris buildup is reduced.

Although these plugs can last up to 110,000 miles without an issue, they are not the most durable or efficient plugs.

On the positive side, single platinum spark plugs are more complex and durable than other metals. The platinum’s longevity and resistance are way higher than copper or iridium. The single platinum spark plugs last up to 110,000 miles, generating a lot of heat that controls and reduces the chamber deposits. Plus, they are cheaper than the iridium spark plugs.  

On the negative side, single platinum spark plugs are not the most efficient, and they work best only on cars with electronic distributor ignition systems.

Pros And Cons: Double Platinum Spark Plugs

The other type of platinum spark plug is the double one. They are very similar to single platinum spark plugs, except for using a laser welded inlay.

This means that not only is their central electrode made of platinum, but the ground electrode is a platinum one.

You should use double platinum spark plugs if your ignition system is a waste system—this type of system fire two sparks in each cylinder. Since there is no ignition, the spark in the exhaust cylinder gets wasted.

Waste spark systems are also beneficial – they are not affected by weather conditions; thus, they are more reliable.

The double platinum spark plugs have many advantages:

  1. They are more durable and more efficient than single plugs;

  2. They are cheaper than the iridium spark plugs;

  3. They are recommended for waste spark systems;

  4. They are highly reliable since they don’t depend on the environment.

On the flip side, they shouldn’t be used for DIS (electronic distribution ignition system)

Iridium Spark Plugs VS Platinum Spark Plugs

If you have trouble deciding between iridium and platinum plugs, you need to consider three critical factors – the cost, the reliability, and the efficiency.

Iridium is harder than platinum, so that an iridium spark plug will outlast the platinum spark plug by twice its mileage. But, with higher mileage comes a higher price. Iridium spark plugs are way pricier than platinum ones. However, the performance improvement is not huge.

When comparing the reliability, the platinum spark plugs are less reliable. While they have good longevity, they don’t offer the most incredible performance. Yet, if your car has an electronic distributor ignition system, then single platinum spark plugs are the right choice for you.

On the other hand, double platinum spark plugs are best suited for cars with waste spark distributor ignition systems. If your primary goal is not to replace the spark plugs every 50 or 60 thousand miles, then you should choose iridium plugs. Iridium spark plugs can last up to 120 thousand miles and offer better performance. The only downgrade is the high cost.

On most modern vehicles, iridium spark plugs are the standard choice. All in all, iridium spark plugs have better performance and longevity than platinum plugs, but they come at a higher cost.  

Which Spark Plugs Are Best For Your Vehicle?

Now that you know all the pros and cons of each spark plug type, it should be hard to determine which type is best suited for your vehicle. If you still have doubts, let’s compare each spark plug type.

Overall, ngk iridium spark plugs are the best. They are the most efficient, and they have the most extended longevity. However, they are the most expensive out of the four types. On the other hand, copper spark plugs are the cheapest and work well on older vehicles.

Yet, copper spark plugs require replacement every 20,000, and they don’t offer the best performance. Since copper is a soft metal, it doesn’t provide a high melting point, and the spark plugs need a nickel-alloy tip. Therefore, the copper spark plugs may be the cheapest, but they are the least efficient and have the smaller lifespan of the four.

The platinum spark plugs are the golden middle. They are not too expensive and don’t have the worst performance. If you want a balance between price and quality, you should go with platinum spark plugs. The double platinum spark plugs are recommended for waste spark systems since they are reliable and do not depend on the weather conditions.

On the other hand, single platinum spark plugs are best for engines with an electronic distributor ignition system since they reduce debris buildup and have a longer lifespan than copper spark plugs.   

Since the spark plugs are an indispensable piece of each vehicle, and they decide how smoothly the car runs, this decision is critical. To help you choose, we recommend you check the owner’s manual and see if there is any specification on which type of spark plugs to use. If it isn’t specified in the manual, you can take your car to the nearest mechanic’s store and ask for advice.


Are Iridium Spark Plugs Better Than Platinum?

Yes, iridium spark plugs are eight times more resistant than platinum spark plugs. Their melting point is 700 degrees higher, and their electrodes have more delicate characteristics. The iridium plugs last at least 25% longer than the platinum spark plugs.

 What Is The Key Drawback Of Platinum Plugs?

Single platinum spark plugs have a disc on their central electrode, while the double spark plugs contain platinum discs on both the primary and ground electrodes.

While platinum spark plugs have better longevity because of their platinum discs, they have a lower ability to conduct heat than copper spark plugs.  

Can I Replace My Old Iridium Spark Plugs With Copper Spark Plugs?

If you have a modern, newer vehicle, it probably has iridium spark plugs or at least platinum plugs. If that is the case, you shouldn’t replace the iridium with the copper spark plug. Downgrading spark plugs can affect your vehicle’s performance negatively.


Spark plugs are a vital part of every vehicle’s combustion process. They are responsible for the vehicle’s performance and function. Choosing which type of spark plugs to use is a frequent debate among manufacturers.

Copper spark plugs are the cheapest but least effective, with the smallest lifespan. Both single and double platinum spark plugs are convenient for a vehicle with waste spark systems and electronic ignition systems. Yet they are less effective than the iridium.

If you have a newer vehicle and can afford them, you should use iridium spark plugs since they have the most extended lifespan and are the most effective out of the four spark plug types.