Should I use iridium or platinum spark plugs?

Iridium spark plugs are generally the better option for longevity and consistent performance, but platinum plugs can be acceptable if your vehicle’s manufacturer specifies them or if upfront cost is a priority. Always follow the OEM recommendation and ensure the heat range and gap are correct for your engine.

What they are and how they work

Iridium and platinum spark plugs differ mainly in the material used for the center electrode and the resulting wear characteristics. Iridium is extremely hard and allows a very fine center electrode tip, which reduces electrode erosion and supports longer service intervals. Platinum plugs are durable as well, but their center electrode is typically thicker than iridium’s, which can result in slightly faster wear in some conditions. Both materials offer advantages over traditional copper plugs and are designed for modern ignition systems, but they are not always interchangeable; matching heat range, reach, and thread size to the engine is essential.

The following list highlights the core differences to consider when choosing between iridium and platinum plugs.

• Iridium spark plugs feature a very fine center electrode made from iridium alloy. This enables lower wear, easier starting, and longer life—often cited as 60,000 to 120,000 miles depending on the model and driving conditions.


• Platinum spark plugs use a robust platinum center electrode that lasts well, typically offering strong performance and durability in many engines, with common intervals around 60,000 miles or more for numerous applications.


• Engine specification and design matter: many modern engines are tuned for a specific plug type. Using the wrong material can affect heat range compatibility, ignition characteristics, and maintenance intervals. Always consult the owner’s manual or a trusted parts guide for the exact recommendation.

In practice, iridium tends to be the preferred choice for most contemporary vehicles, especially where longevity and performance across high-mileage use are priorities. Platinum remains a viable alternative when the manufacturer specifies it or when upfront cost is a determining factor.

Choosing based on your vehicle

To determine which type is right for your car, consider how the vehicle is designed to operate and your typical driving pattern. The following guidelines help frame the decision.

Guidance for selecting spark plug material includes the following considerations:

• Manufacturer specification: Always use the exact plug type, heat range, and gap recommended in the owner’s manual or parts guide. Substituting the wrong type can affect performance and longevity.


• Driving style and climate: If you do a lot of cold starts, frequent short trips, or operate in extreme conditions, iridium plugs often provide more reliable ignition and longer life. For many everyday drivers, platinum can be adequate if specified by the OEM.


• Cost and maintenance: Iridium plugs cost more upfront but may reduce maintenance frequency due to longer life. Platinum plugs are cheaper upfront and can be suitable for drivers who replace plugs more often or on a tight budget.


• Ignition system compatibility: Some modern ignition systems rely on specific electrode geometry and heat range. Ensure compatibility to avoid timing or misfire issues.

Bottom line: start with the manufacturer’s recommendation, then weigh your driving demands and budget. If in doubt, consult a dealership service department or a trusted automotive technician.

Summary

Iridium spark plugs are typically the superior choice for longevity and consistent performance on most modern engines and are often the default recommendation. Platinum plugs offer solid durability at a lower upfront cost and can be appropriate when the OEM specifies them or when budget considerations are paramount. Regardless of material, matching the correct heat range, reach, and gap to the engine is essential, and following the manufacturer’s specification remains the best guidance for reliability and efficiency.

Do iridium spark plugs really make a difference?

Yes, iridium spark plugs are generally considered better than copper and platinum because their durability allows for a fine-wire center electrode that creates a more concentrated and efficient spark, leading to smoother performance, better fuel economy, and a longer lifespan. This makes them an excellent choice for high-performance and modern engines. 
This video explains the benefits of iridium spark plugs: 1mCountermanYouTube · Dec 17, 2021
Advantages of iridium spark plugs

• Increased durability: Iridium is an extremely hard and durable precious metal, making the plugs resistant to heat and erosion. This allows them to last much longer, often up to 100,000 miles or more. 
• Improved performance: The fine-wire center electrode requires less voltage to create a spark, which can lead to a more complete combustion. This can result in smoother engine operation, better throttle response, and a more stable idle. 
• Better fuel efficiency: A more complete combustion can lead to a modest improvement in fuel economy. 
• Superior spark: Iridium plugs provide a more powerful and consistent spark, which is especially beneficial for high-performance or modern engines with sophisticated ignition systems. 
• Corrosion resistance: Iridium's high resistance to corrosion helps the spark plug last longer when exposed to the reactive compounds found in exhaust gases. 

When to consider other options

• Cost: Iridium spark plugs are a premium option and have a higher price point than other types. 
• Older engines: For some older engines, particularly those with older, less sophisticated ignition systems like a distributor, copper or platinum plugs may be a more suitable and cost-effective choice, as the benefits of iridium may not be as pronounced. In some cases, an older engine may not be able to fully utilize the benefits of iridium plugs. 

This video discusses the comparison of different spark plug types: 59sFCP EuroYouTube · Mar 25, 2024

What happens if you use platinum spark plugs instead of iridium?

If you use platinum spark plugs instead of iridium, you may experience reduced performance and shorter lifespan, especially in high-performance or modern engines. Iridium is stronger and has a higher melting point, making it more durable and efficient, while platinum is more affordable and suitable for older "waste spark" ignition systems. The best choice depends on your vehicle's specific requirements, so check your owner's manual to determine the recommended spark plug type.
 
Potential effects of using platinum instead of iridium

• Shorter lifespan: Iridium plugs can last up to 100,000 miles or more, while platinum plugs typically last between 30,000 and 60,000 miles. 
• Reduced performance: Platinum plugs may not provide the same level of consistent performance as iridium plugs, especially in high-performance engines. They may also wear down faster, which can lead to misfires. 
• Less efficient ignition: Iridium is a stronger metal that can handle higher temperatures and pressures, making it more reliable for high-performance applications. Platinum can also produce a concentrated spark but is not as durable as iridium. 
• Incompatibility with certain systems: If your car was designed with iridium plugs, switching to platinum may result in reduced efficiency and performance. However, if your car has an older "waste spark" system, platinum plugs might be a suitable and more budget-friendly option. 

What to consider before switching

• Check your owner's manual: Always consult your vehicle's owner's manual to confirm the type of spark plug it requires. 
• Consider your vehicle's performance needs: For a high-performance engine or a vehicle with modifications like a turbocharger, iridium plugs are generally the better choice. 
• Weigh the cost: Iridium plugs are typically more expensive, but their longer lifespan can make them a better value over time. Platinum plugs are more affordable upfront but may need to be replaced more frequently. 

What is the disadvantage of iridium spark plugs?

The main disadvantages of iridium spark plugs are their high cost, the potential for damage due to the brittle electrode, and the fact that they cannot be cleaned, meaning a fouled plug must be replaced. While they are very durable, their high price may not be justifiable if the extended life isn't needed, and counterfeit versions can be problematic. 
Cost

• Higher initial price: Iridium plugs are significantly more expensive than copper or standard platinum plugs. 
• Questionable value for some engines: The added expense may not offer a noticeable performance benefit in older or less demanding engines, especially when compared to a quality platinum plug. 

Fragility and installation

• Delicate electrode: The fine-wire iridium electrode is brittle and can be easily damaged during installation if the plug is not handled with care. 
• Risk of breakage: Damage to the electrode can negate the benefits of the plug almost immediately. 
• Precise handling needed: Improper handling can cause cracks or impact damage to the fragile tip. 

Maintenance and cleaning

• Cannot be cleaned: Unlike some other types of spark plugs, iridium plugs cannot be cleaned. If they become fouled, they must be replaced entirely. 
• Limited cleaning options: This makes them a poor choice for engines that are prone to fouling. 

Other considerations

• Counterfeit products: The high cost makes them a target for counterfeiting, so it is important to buy from reputable dealers to ensure quality. 
• Engine compatibility: While ideal for modern, high-performance, or high-energy ignition systems, they are not necessarily an upgrade for every engine. It's often best to stick with the manufacturer's original equipment recommendation unless there's a specific performance goal, like longer life. 

Should I get iridium or platinum spark plugs?

Choosing iridium is advisable as it is a harder metal, which provides better durability compared to platinum for extended service intervals. Additionally, iridium is a superior electrical conductor than platinum, resulting in improved spark performance.