
Copper vs Iridium vs Platinum Plugs
No car will start without spark plugs. As the name suggests, they spark off the electricity that causes combustion used in igniting the car. Getting the right spark plugs for your car is a priority because it is linked to engine performance.

Poor quality and spark plugs that do not match your engine design could lead to numerous performance issues, including engine misfire and cold starting. There are four types of spark plugs:
- Copper
- Iridium
- Platinum
- Double platinum
These are different types of electrode materials that are used to manufacture them.
The number of cylinders in a car will determine how many spark plugs the engine will need. Despite the different materials used for different spark plugs, the functions remain the same. However, in choosing between Copper, Iridium and Platinum plugs, you may want to put into consideration a few factors. Spark plugs withstand extreme heat so the heat rating will be a factor, alongside performance.
Copper Spark Plugs
Copper is an excellent conductor of heat. Despite being a good conductor of heat, it also has a low melting point, hence the reason it has to be coated with the nickel alloy. The electrodes in the spark plug conduct the electricity spark into the combustion chamber to start the car. Copper spark plugs are the best in performance but do not outlive other types.
Among the three spark plugs, copper ranks as the best in performance as well. A normal spark plug will produce chemical corrosion but the copper core reduces the high-temperature eels and reduces corrosion levels while at it. Change of copper spark plugs must be done at the very least, every 20,000 miles.
Copper spark plugs are perfect for some older model cars and will not use any other material. Remember to check your car user manual and ensure that you can use any other plugs. If it requires that you only use copper spark plugs, then you cannot upgrade to any other.
Why should one go for copper spark plugs?
- They are affordable and easily accessible.
- They run cooler and give off more power in engine performance.
- They can be used in older car models, as old as pre 80’s car models.
Why you should not go for the copper spark plugs?
- They are not durable. The outside of copper spark plugs is coated with nickel-alloy that is fused to the copper electrodes core. The nickel- alloy material wears out fast because it is not as hard as the other metals.
Platinum Spark Plugs
Platinum spark plugs are an upgrade from the copper ones. They come in two types, Single-Platinum and Double-Platinum. There is a question on whether the double-platinum is twice as good as the single or is there just a negligible difference in performance and longevity between them.
Platinum is a much harder metal than the nickel alloy that is used to hold the edges in the copper plug. This goes a long way in prolonging the lifespan of these plugs. Single platinum plugs are perfect for newer car models with Electronic Distributor Ignition Systems.
The double-platinum plugs are an upgrade from the single platinum. Where the single platinum plug has a platinum disc welded to the center electrode the double has a platinum disc on both the side and center electrodes.
If your car manual says to use single platinum plugs, do not use the copper ones, despite the difference in pricing. You may use the double-platinum as an upgrade. This applies to the double-platinum, if your car manual recommends them, do not downgrade to single platinum or copper, but you may use the iridium spark plugs.
Advantages of Platinum Spark Plugs
- They last much longer than copper spark plugs and give a better performance, going up to about 25,000 miles.
- They maintain a stable operating temperature under any engine load.
Except for the fact that platinum spark plugs are slightly more expensive than copper, there do not have any major disadvantages.
Iridium Spark Plugs
Iridium is a very hard silvery metal that is unreactive, just like gold. It is also extremely dense. It is the second densest metal and has a very high melting point. It is very brittle and hence, not easy to use in its natural form.
Because of this, it is mostly used as a hardening agent for platinum. Together they form a formidable alloy that is used in making iridium spark plugs. It is also the most corrosive resistant metal.
Iridium spark plugs are highly superior to double platinum spark plugs and cannot compare to the copper ones. They feature a fine wire center electrode that is designed to conduct electric energy much better and increase firing efficiency.
Highly innovative technology goes into integrating the iridium into the superior material and this means they are more costly than copper or platinum They are well suited for high-performance engines.
Advantages of Iridium Spark Plugs
- They are durable. Being a long-lasting metal, these spark plugs have a life span of up to 25% longer than double platinum plugs.
- Increased engine performance especially if you are upgrading from a copper or single platinum set.
- You will notice a considerable reduction in emissions.
A disadvantage is that they are quite pricey, at almost thrice the price of copper spark plugs.
factors to consider when choosing the spark plug
In choosing the materials suitable for your car spark plugs, you will need to put into consideration several factors.
Needs of the car as specified by the manufacturer
Using spark plugs below what has been recommended by the manufacturer will cause you extensive engine trouble. Using Iridium spark plugs that give you the best value for money will be economical in the long run.
Adhere to the instruction given by the manufacturer and if there is need to change, go with an upgrade of the recommended spark plug material.
Size of the spark plugs
Ensure that you use the right size of spark plugs and the gapping is done just right. Ones that are too small and with poor gapping will cause you poor gas mileage as well as fouling. The right size of spark plugs will ensure the right air/fuel ratio goes into combusting for firing efficiently.
There are plenty of different manufacturers of spark plugs in the market. Shop around, either physically or online to look at reviews of different brands if you are looking to change to a different brand.
They are quite basic car maintenance items and can be a do it yourself item if you are a handy person. Because they are inexpensive and will go a long time before you have to replace them, it is wise to always keep a spare set in case anything goes wrong and you have to replace them.
Check the condition of your spark plugs regularly to know when they are ready for change. When they develop a black or ashy coating around the top of the center electrode, then you must replace them with a new set.
Ensure you replace the spark plug wire with every spark plug change. There is a chance that if your spark plugs were faulty, they damaged the wires too. Play it safe for optimum engine safety and change both.