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How Long Do Platinum Spark Plugs Last? (+6 FAQs)

March 25, 2022

Spark plugs contribute to engine performance and are available in many different materials — with copper, platinum, and iridium plugs being the ones you’ll likely see most often. 

Now, you may wonder, why is a precious metal like platinum used in a spark plug? 
And how long do platinum spark plugs last?

We’ll answer those questions in this article. We’ll also see whether double platinum spark plugs last longer, and cover some of the most important FAQs.

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Let’s begin.

How Long Do Platinum Spark Plugs Last?

Platinum is a precious metal, so the amount used on a platinum spark plug varies, influencing its longevity. 

The typical platinum spark plug can last up to 60,000 miles, though long-life variations boast up to 100,000 miles. However, even 60,000 miles of use is still longer than the copper spark plug, which usually only lasts up to 30,000 miles or so. 

Why do they last much longer?
Platinum spark plugs usually have a copper core, just like a standard copper plug. Copper is soft, so the copper plug has nickel alloy on its center electrode to protect it from wear. 

The platinum spark plug uses a platinum disc on its center electrode. Platinum is a much harder metal than copper, with a much higher melting point. This allows platinum plugs to wear better than copper plugs. 

Additionally, the platinum plug generally runs hotter, which means any contaminant buildup in the combustion chamber is more efficiently burnt off. This prevents spark plug fouling, helping to maintain better fuel economy and efficiency in the long run. 

Now, what about the double platinum? 

Do Double Platinum Spark Plugs Last Longer Than Single Platinum?

Double platinum spark plugs have a platinum disc on the center electrode and on the ground electrode (side electrode), which improves the wear resistance, thus extending the plug’s lifespan.

This spark plug type is often used in “waste spark” ignition systems, which fire twice the rate of standard distributor-based or coil-on-plug-based ignition systems. 

Double platinum spark plugs are generally more durable than the single platinum and are cheaper than iridium ones. Like long life spark plugs, they can last about 100,000 miles. 

However, spark plug lifespan is also influenced by engine type or driving style. A high-performance engine may wear off even a double platinum spark plug faster than usual. The same goes for frequent short trips or idling. 

Now, let’s look at some common questions on platinum spark plugs.

6 FAQs On Platinum Spark Plugs

Here are the answers to some of the most frequently asked questions: 

1. What Are Different Spark Plug Materials?

Spark plugs typically feature a highly conductive copper core (these are sometimes called a copper core spark plug). 

However, copper is soft with a low melting point, so the electrodes are covered with harder metals with higher melting points — typically nickel alloy for the conventional spark plug. 

The term ‘copper spark plugs’ is somewhat misleading, as it usually references conventional spark plugs with a nickel alloy electrode.

Precious metals like platinum or iridium are frequently used as these metals significantly reduce wear on the spark plug electrodes. Other precious metals used to improve spark plug durability include silver, ruthenium, and gold-palladium. 

2. Do Iridium Spark Plugs Last Longer Than Platinum Ones?

Iridium is a strong, hard metal with a melting point that’s 1220°F higher than platinum. This gives the iridium plug excellent wear resistance and can last up to 25% longer than comparable platinum ones. 

The iridium spark plug is characterized by a very fine central electrode that produces a concentrated flame capable of burning fuel very efficiently. The only drawback to the iridium plug is its high price tag.

3. Can I Use A Different Platinum Spark Plug Than My OEM Plug?

An old spark plug doesn’t necessarily need to be replaced with the same brand as the OEM plug. Technically, any new spark plug will do, provided that it fits correctly and has the right engine heat range.

What about metal type? Can you change it?
The best spark plug for your car’s engine is often one that is the same type as the original. Platinum plugs should be replaced with platinum, iridium plugs with iridium, and so on — as that’s what your engine was designed to work with. 

Never downgrade to cheaper copper plugs if your car uses platinum ones. However, sometimes you can upgrade from platinum to iridium plugs — but check with your owner’s manual first. 

And if your car uses double platinum spark plugs, don’t downgrade to single ones. 

Additionally, some older cars designed for copper may not work well with platinum spark plugs. So upgrading to platinum spark plugs might not always be advisable either. 

4. Are Platinum Spark Plugs Easy To Remove?

Not always. 
Think about it. The spark plug has been in the cylinder head for many miles — even a regular spark plug would likely sit in the cylinder head for at least 20,000 miles. Your platinum spark plug would have been in the cylinder head much longer.

In all that time, carbon and corrosion would have developed. This could make it difficult to unscrew the spark plug. Also, if you’re not careful, the removal process could damage the threads in the aluminum cylinder head of most modern cars. 

To help prevent corrosion between the steel spark plug threads and aluminum cylinder head threads, many spark plugs now ship with zinc or nickel-plated threads. 

If you’re thinking of using anti-seize to prevent corrosion on new spark plug threads — it isn’t advisable. Anti-seize can act as a lubricant, increasing the risk of over-tightening a spark plug. It can also contaminate a spark plug electrode if too much is applied, causing fouling and misfires.

5. What Happens If I Don’t Replace Them?

Just like a regular spark plug, over time and use, the platinum spark plug gap between the center electrode and ground electrode will widen. The spark plug will weaken and eventually fail. 

So if you don’t replace it, you’re up for a myriad of engine issues, like:

Some of these issues may lead to costly engine repairs, and can easily be averted with a spark plug replacement in the first place. 

6. Should Spark Plug Wires Be Changed With Spark Plugs?

Generally, yes. 
Spark plug wires send high voltage from the ignition coil to the spark plugs, and they wear out just like spark plugs do. 

The carbon fiber in an old spark plug wire would break down over time, creating high resistance, which isn’t good for your engine. 

High resistance in the spark plug wire degrades the spark plug’s electric spark. As a result, you’ll get poor combustion, misfires, increased emissions, and reduced gas mileage. 

If left unattended, a worn spark plug wire could leak voltage to adjacent engine parts, causing severe performance issues and possibly even failure of ignition components. So, it’s advisable to replace your spark plug wire sets together with worn spark plugs.

Wrapping Up

Platinum spark plugs represent a good middle ground between cheaper copper and expensive but long-lasting iridium ones. The platinum may not last as long as the iridium spark plug, but you still won’t need a spark plug replacement for quite some time. 

And when the time comes for a spark plug replacement, you can always get help from RepairSmith to switch out your worn spark plugs!  

RepairSmith is a mobile repair and maintenance service, available seven days a week, with an easy online booking process

Contact us, and our ASE-certified mechanics will be happy to drop by your driveway and deal with any car issues you have.