How Long Do Iridium Spark Plugs Last? (Explained!)

Every spark plug can give you a lot of time, but they do not last forever, so what about these iridium spark plugs? Let us find out.

So how long do iridium spark plugs last? An iridium spark plug can last up to one hundred thousand (100,000) miles or longer.

Again, every spark plug in the market is made to last for a long time. However, the lifespan of each spark plug is different from one another. Some spark plugs can only last for many miles. 

Some spark plugs can also last for a very long time. So the longevity of each spark plug is different from one another. 

So today, we will focus on the lifespan of iridium spark plugs. Let us get started.

How Long Do Iridium Spark Plugs Last

How Often Should Iridium Spark Plugs Be Replaced?

Iridium spark plugs are fitted with the feature of longevity. You can replace your iridium spark plugs for about one hundred thousand (100,000) miles. However, the mark can be longer, and it can also be shorter. 

Therefore, it is not to strictly follow the recommended miles. You have to check your spark plugs to know when is the perfect time to change your spark plugs. You also have to think of your engine performance. 

If your spark plug needs replacement, you will experience that through your engine’s performance. Just look for any odd behavior and if you are experiencing some weird behavior in your vehicle. That will tell you when you should change your spark plugs.

How Many Miles Are Iridium Spark Plugs Good For?

Iridium can be good up to one hundred thousand (100,000) miles. So these iridium spark plugs are for longevity. If you have those conventional spark plugs, they can only last for about twenty thousand (20,000) miles to fifty thousand (50,000) miles. 

But since you have the iridium spark plugs, they are known to have that long-life spark plugs; they can last for about sixty thousand (60,000) miles to one hundred fifty (150,000) miles.

How Are Iridium Spark Plugs Compared To Others?

Iridium spark plugs are known to be stronger eight times if compared to platinum spark plugs. So there are four other types of spark plugs. Let us discuss each one.


This copper is cheaper than the iridium spark plugs. This is a very common type of spark plug. 

This is because they are cheaper compared to iridium spark plugs. That is why people prefer to use this instead of any other type of spark plug.


The Platinum spark plug is harder than a nickel allows. So it is a hard spark plug, and it can also be as hard as the iridium spark plugs.

It can also last up to one hundred thousand (100,000) miles. It is also the same with iridium spark plugs in terms of longevity.

Double Platinum

Double platinum is recommended if your distributor ignition system is a wasted spark system.  The double-platinum has a double-disc on its electrode. Compared to the iridium spark plugs, you must choose the iridium.


This silver spark plug is not very common. This type of spark plug has a silver-coated electrode tip. This cannot be compared to iridium spark plugs because it is less durable in terms of longevity. 

If you are into a longer lifespan for your spark plugs, do not choose these silver spark plugs. Aim for iridium spark plugs or platinum spark plugs instead.

What Are The Best Iridium Spark Plugs?

This will depend on everyone because every person has their preferences. However, if we can pick one, we can go with NGK 6619 iridium ix spark plugs. 

This is known to be the best iridium spark plug. These iridium spark plugs can offer you durability, and they can give you dependability. It is also very fuel-efficient.

How Long Do Denso Iridium Spark Plugs Last?

The Do Denso iridium spark plugs have an iridium center electrode. It also has a traditional nickel ground electrode construction. 

With that, the ground electrode will wear out first. So with Do Denso iridium spark plugs, you can last up to sixty thousand (60,000) miles to eighty thousand (80,000) miles.

How Long Does Bosch Iridium Spark Plugs Last?

The Bosch iridium spark plugs can last up to one hundred thousand (100,000) miles. Of course, the miles can vary with some other factors. The Bosch iridium spark plug series is bringing long life to the plugs. 

So it is a good choice if you want a spark plug that would last long. This can offer you a long time before replacement.

How Long Do AC Delco Iridium Spark Plugs Last?

The AC Delco Iridium spark plugs can also last for about one hundred thousand (100,000) miles. So this spark plug can be suitable for a performance drive, and it is also suitable for older vehicles. So this is also up for longevity. 

You can try this. However, you can always replace your spark plugs even if they still have not reached the miles mark. Other factors will disrupt the lifespan of your spark plugs.

How Long Do Ruthenium Spark Plugs Last?

The Ruthenium spark plugs can also last long in one hundred thousand (100,000) miles. But, of course, you have to read first your owner’s manual for these spark plugs. The high efficient spark plugs will last longer, of course. 

The miles can vary, of course. You can change your spark plugs longer than one hundred thousand (100,000) miles, or it can be lower than that.


The iridium spark plugs are considered to be the best kind of spark plug when it comes to handling the heat. Compared to a copper spark plug or a platinum spark plug, the iridium spark plug can give you a better performance. 

Iridium is harder than platinum. But it can offer much better performance. The copper is still more conducive to platinum. 

A spark plug is crucial in maintaining the smooth run of your vehicle. It may be small, but it contributes a lot to the performance of your vehicle. The iridium spark plug is a good choice, and it can last up to one hundred thousand (100,000) miles.



Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more