Home
Blog Car Care Advice A Guide To Iridium Spark Plugs (Benefits, 4 FAQs)
Car Care Advice

A Guide To Iridium Spark Plugs (Benefits, 4 FAQs)

Looking for a mechanic near you for maintenance or repair? RepairSmith brings the shop to you. Get a free instant quote today.
Get a quote

Iridium spark plugs are thought to be the most durable and best-performance category of spark plugs globally. They can last up to 120,000 miles. 

But what makes iridium spark plugs different? 
And what are the benefits of using iridium plugs? 

In this article, we’ll answer these questions in detail and address some FAQs that you may have if you’re planning to shift to iridium spark plugs. 

This Article Contains: 

Let’s begin!

What Are Iridium Spark Plugs?

Spark plug technology has come a long way since the humble copper spark plug

The spark plug form factor has remained generally the same — a center electrode, a ground electrode, an insulator, a metal casing or shell (which then connects to a spark plug boot, linking to the ignition coil). However, variations on the tip offer different levels of performance.

Now, iridium spark plugs use a precious metal called iridium at the tip of the plug’s center electrode. 

Since iridium is a highly durable metal with a very high melting point (2,446 °C), it ensures that these plugs offer complete combustion and superior engine performance. Their insulator tip and other parts also have better resistance for a higher heat range. 

Iridium spark plugs are wear-resistant, so you can continue to drive your vehicle without changing them too often. 

Moreover, iridium spark plugs have a smaller fine wire center electrode than a standard copper spark plug. This helps ensure a more concentrated spark to power an engine faster.

Next, we’ll cover the advantages of using iridium spark plugs. 

Benefits Of Using Iridium Spark Plugs

Here are some of the perks of having iridium spark plugs installed on your vehicle:  

1. Extended Lifespan

Iridium plugs have the longest lifespan compared to a standard spark plug (copper core plug) or platinum plug. An iridium spark plug can last up to 120,000 miles, depending on your vehicle and driving conditions. 

2. Enhanced Durability

Iridium is much harder and stronger than platinum, making it more durable to withstand the high voltage coming through the spark plug wire

Iridium spark plug parts are also corrosion-resistant. So, the extreme conditions inside the combustion chamber can’t easily wear out their insulator tip, spark plug threads, center electrode, and the ground electrode. 

Corroded spark plug threads can cause a spark plug to get stuck in a cylinder head, making replacement very difficult. In worst-case scenarios, the cylinder head is damaged and needs replacement too.

3. Better Ignition Experience 

The smaller iridium center electrode of the plug offers a stronger and more concentrated spark, allowing quicker combustion. These plugs have superior ignitability and require less voltage from the ignition coil, leading to fewer misfires. 

You’ll also experience less lag when you press down on the pedal and fewer delays in the initial engine startup. This is especially beneficial with the cold-cranking amps of your battery during winter.

4. Improved Fuel Economy

Iridium spark plugs offer improved ignition, allowing the fuel to burn more efficiently inside the combustion chamber. As a result, you get better fuel efficiency (10-20% for gasoline engines.)

5. More Engine Power

The technology of iridium plugs can improve the performance of modern engines during challenging driving conditions. You experience stable idling and a more controlled driving experience, especially in cars with automatic transmissions.

While iridium spark plugs have several significant advantages, they also have a few downsides. 

Iridium Spark Plug Drawbacks

Let’s have a look:

1. Higher Costs 

An iridium spark plug can cost anywhere between $20-$100. This can be expensive when replacing all the spark plugs for smaller cars. But, the higher cost is justified by the added longevity of iridium plugs. 

However, a smaller engine may not notice any performance upgrade when shifting from a standard plug (copper spark plug) to an iridium plug. You could get the same results with cheaper spark plugs too. 

2. Iridium Dust Is Susceptible To Corrosion And Flammability

You must install iridium spark plugs carefully because any dust from its parts due to accidental scraping increases the chance of ignitability. Iridium dust is also more susceptible to corrosion and fluorine contamination inside the combustion chamber. 

Clearly, the perks of using iridium plugs outnumber the drawbacks. 

So, while you decide if iridium spark plugs are the right spark plug for your vehicle, let’s answer some related questions. 

4 FAQs On Iridium Spark Plugs

Here are some commonly asked questions about iridium plugs: 

1. How Are Iridium Spark Plugs Different From Normal Ones?

Most spark plugs are copper core spark plugs — meaning they have a copper core. A regular spark plug has a copper center electrode with a nickel alloy coating. 

On the other hand, an iridium plug has an iridium tip on the center electrode. Double iridium spark plugs also have a coating on the ground electrode. 

The iridium electrode inlay is more durable, with a higher melting point that helps increase the service life of a plug. It can also offer better performance and fuel efficiency than a normal plug.  

Also, while a conventional spark plug or a copper plug can last 20,000 to 30,000 miles, an iridium spark plug can offer 100,000 miles or more before you need a replacement

2. What Are Other Materials Used In Spark Plugs?

A normal plug generally has a copper core center electrode with different metal coatings to protect against wear. 

Copper spark plugs (with nickel alloy electrodes) are often installed as original equipment in modern engines with higher compression ratios. However, this conventional spark plug has a low melting point and wears out faster. 

Platinum spark plugs are another common spark plug variety. Platinum is harder than copper or nickel alloy and helps reduce the wear of a spark plug caused by high voltage.

Platinum spark plugs come in two versions — single and double platinum. 

The single platinum spark plug only has a platinum coating on the center electrode. A double platinum spark plug has a platinum disc on both the ground and center electrode. 

Double platinum spark plugs (and double iridium spark plugs) are usually recommended for a waste spark distributor ignition system.

3. What’s The Difference Between An Iridium And Platinum Plug? 

Iridium is considered six times harder and eight times stronger than platinum. Its melting point is also 700°F higher than platinum. So, iridium spark plugs can last 25% longer (up to 120,000 miles) than platinum ones (up to 100,000 miles.)

An iridium spark plug features a finer electrode inlay to produce a more concentrated spark. As a result, it offers a better quality flame for more efficient combustion than a platinum spark plug

However, since iridium is a rare and more precious metal than platinum, these plugs are more expensive.

4. What’s The Best Spark Plug Material For My Vehicle?

Ideally, you should check your owner’s manual to determine the recommended spark plug type. 

Consult a professional mechanic or an ignition specialist to determine if you can upgrade to an iridium spark plug. You can also opt for double iridium spark plugs.

Manufacturers like NGK, Denso, Champion, or Autolite spark plugs offer a variety of technology. For example, you could opt for more specialized NGK iridium spark plugs like Iridium IX or Laser Iridium for superior ignitability and better performance. 

That said, you should never downgrade to platinum or copper if your vehicle manual specifies an OEM iridium spark plug. If you do so, you risk poor ignition and misfires, especially in high performance vehicles, like a Cadillac CTS V. 

Final Thoughts

Spark plug technology plays a critical role in the combustion chamber. They can affect your engine’s efficiency and fuel economy. 

If you plan to switch to an iridium spark plug from a standard spark plug or other types, you should weigh the benefits to pick the right spark plug.

And if you want to consult a professional or need help with the spark plug replacement, contact RepairSmith!

We’re a convenient mobile auto parts repair and maintenance solution offering competitive, upfront pricing. Our expert mechanics can guide you on the right replacement spark plugs and perform the replacement right in your driveway. 

Fill out this form for an accurate cost estimate for spark plug replacement or any other automotive repair!