Best Iridium Spark Plugs of 2025

Robert Reyes Avatar
Robert Reyes
Last Updated: Jan 9, 2025

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Iridium spark plugs are a popular choice for car enthusiasts who want to improve their engine's performance. Made with a small but durable iridium electrode, these spark plugs are designed to last longer than traditional copper spark plugs. They also provide a stronger spark, which can lead to better fuel efficiency and more horsepower. Iridium spark plugs are available for a wide range of vehicles, including cars, trucks, and motorcycles. While they may be more expensive than other spark plugs, many drivers believe that the improved performance and durability is worth the investment.

At a Glance: Our Top Picks

NGK Iridium IX Spark Plug, 4 Pack Cover #TOP 1
NGK Iridium IX Spark Plug, 4 Pack
ftb score rating icon 9.9
NGK 6619 Iridium Spark Plugs Cover #TOP 2
NGK 6619 Iridium Spark Plugs
ftb score rating icon 9.8
NGK Iridium IX Spark Plug Cover #TOP 3
NGK Iridium IX Spark Plug
ftb score rating icon 9.6

Top 10 Iridium Spark Plugs

#TOP 1

NGK Iridium IX Spark Plug, 4 Pack

NGK
LKR7DIX-11S
NGK Iridium IX Spark Plug, 4 Pack Cover
NGK LKR7DIX-11S Iridium IX Spark Plug (93175 Iridium Ix), 4 Pack

The NGK LKR7DIX-11S Iridium IX Spark Plug is designed for performance enthusiasts, offering extreme ignitability and improved throttle response. Its laser-welded fine Iridium tip ensures high durability and a consistently stable spark, while the tapered ground electrode minimizes electrical quenching effect. The corrugated ribs on the longer insulator prevent flashover, and the triple gasket seal eliminates combustion gas leakage. The Iridium alloy has an extremely high melting point, making it durable to heat and electrical wear, perfect for high-performance engines. The Trivalent Metal Plating provides superior anti-corrosion and anti-seizing properties.

What We Like
Improves throttle response
Ensures a consistently stable spark
Prevents flashover and combustion gas leakage
High durability to heat and electrical wear
Provides superior anti-corrosion and anti-seizing properties
#TOP 2

NGK 6619 Iridium Spark Plugs

NGK
6619
NGK 6619 Iridium Spark Plugs Cover
NGK 6619 Iridium Spark Plugs LFR6AIX-11 - 6 PCSNEW

NGK 6619 Iridium Spark Plugs are designed to operate over a wider heat range than ordinary plugs, resist carbon buildup and pre-ignition, and eliminate the possibility of combustion gas leakage with its patented triple gasket sealing process. These spark plugs are ideal for anyone who wants a durable and reliable option for their vehicle.

What We Like
Durable
Reliable
Wide heat range operation
Resists carbon buildup and pre-ignition
Eliminates combustion gas leakage
#TOP 3

NGK Iridium IX Spark Plug

NGK
LKAR7BIX-11S
NGK Iridium IX Spark Plug Cover
NGK LKAR7BIX-11S Iridium IX Spark Plug (93501 Iridium Ix), 4 Pack

The NGK Iridium IX Spark Plug is designed for performance enthusiasts, offering improved throttle response, anti-fouling, and extreme ignitability. The spark plug features a 0.6mm laser-welded fine iridium tip that ensures high durability and consistent, stable sparks. A tapered ground electrode helps minimize the electrical quenching effect, while a longer insulator nose prevents fouling. The spark plug also has superior anti-corrosion and anti-seizing properties thanks to its trivalent metal plating.

What We Like
Improved throttle response
High durability
Superior anti-corrosion and anti-seizing properties
#TOP 4

NGK Iridium IX Spark Plug

NGK
LFR5AIX-11
NGK Iridium IX Spark Plug Cover
NGK (4469) LFR5AIX-11 Iridium IX Spark Plug (8 Pack)

NGK Spark Plug 8 Pack is a top choice for your vehicle's ignition system. With NGK's reputation for quality and performance, these spark plugs offer the best combination of longevity and reliability. As the world's largest supplier of OEM spark plugs, NGK ensures that you get the quality, durability, and reliability you expect from an OEM manufacturer. Before purchasing, make sure these spark plugs fit your vehicle's engine and drivetrain. This 8-pack of spark plugs is a convenient solution for ensuring your vehicle runs smoothly.

What We Like
Quality Performance
Longevity
Reliability
#TOP 5

Autolite Iridium XP Spark Plugs, XP5683 (4 Pack)

XP5683-4PK
Neutral
4-Pack
Autolite Iridium XP Spark Plugs, XP5683 (4 Pack) Cover
Autolite Iridium XP Automotive Replacement Spark Plugs, XP5683 (4 Pack)

The Autolite Iridium XP automotive replacement spark plug provides an extended change interval of up to 100,000 miles, making it extremely durable. The spark plugs are designed for maximum fuel efficiency with a finewire iridium centerwire tip and laser welded technology. The finewire electrodes provide more focused and consistent ignitability and result in less fuel consumption. With a platinum protected ground wire and V-trimmed ground electrode, these spark plugs provide optimal performance in all ignition types, including DIS systems.

What We Like
Durable with an extended change interval of up to 100,000 miles
Designed for maximum fuel efficiency with finewire iridium centerwire tip and laser welded technology
Provides better overall ignitability and optimal performance
#TOP 6

6 New NGK Iridium IX Spark Plugs LFR5AIX-11 # 4469

NGK
4469
6 New NGK Iridium IX Spark Plugs LFR5AIX-11 # 4469 Cover
6 New NGK Iridium IX Spark Plugs LFR5AIX-11 # 4469

The NGK Iridium IX Spark Plugs LFR5AIX-11 # 4469 offer an extreme performance upgrade to OEM spark plugs, with a lifespan of 40,000 to 50,000 miles. They feature a fine-wire Iridium center electrode and nickel-alloy terrain electrodes for maximum engine and torque, and are suitable for fuel-injected and turbo engines. Additionally, the precision laser electrode construction ensures reliable performance.

What We Like
Provides an extreme performance upgrade to OEM spark plugs
Features a fine-wire Iridium center electrode and nickel-alloy terrain electrodes for maximum engine and torque
Suitable for fuel-injected and turbo engines

Bosch Automotive (9614) OE Fine Wire Double Iridium Spark Plug

9614
Double Iridium
Bosch Automotive (9614) OE Fine Wire Double Iridium Spark Plug Cover
BOSCH 9614 OE Fine Wire Double Iridium Spark Plug - Pack of 4

Bosch Double Iridium Spark Plug is a high-performance spark plug designed for 07-10 Acura CSX, 07-09 Acura MDX, 05-08 Acura RL, 02-06 Acura RSX, 04-08 Acura TL, 04-08 Acura TSX, 03-07 Honda Accord, 02-11 Honda Civic, 02-09 Honda CR-V, 03-11 Honda Element, and 14 Honda Fit. It features a Double Iridium firing pin and ground electrode inlay, which provide 4X longer service life compared to standard copper plugs. The 0.6mm fine wire firing pin provides superior ignitability and performance. The 360 Degree continuous laser weld fuses corrosion-resistant iridium firing pin to the base for increased durability. With its OE design, Bosch Double Iridium Spark Plug is a pre-gapped replacement that delivers optimum fit, form, and function. The 7-year performance satisfaction guarantee ensures that you'll get your money's worth.

What We Like
Durable
Long service life
Superior ignitability
#TOP 8

NGK Iridium Spark Plug LTR6IX-11 - 6 PCS

NGK
LTR6IX-11
NGK Iridium Spark Plug LTR6IX-11 - 6 PCS Cover
NGK # 6509 Iridium Spark Plug LTR6IX-11 - 6 PCSNEW

This NGK Iridium Spark Plug LTR6IX-11 comes in a set of 6 pieces and provides better performance. It is a high-quality product from a reputable brand that guarantees superior performance. The iridium construction makes it highly durable and long-lasting. Additionally, it ships for free to anywhere in the USA and territories, making it a great deal.

What We Like
Provides better performance
High-quality product from a reputable brand
Durable and long-lasting iridium construction
Ships for free to anywhere in the USA and territories
#TOP 9

NGK Spark Plugs TR5IX

NGK
7397
NGK Spark Plugs TR5IX Cover
(8-Pack) NGK Spark Plugs TR5IX (Stock # 7397)

NGK 8-Pack Spark Plugs are highly recommended for your vehicle. These spark plugs, known for their performance and durability, are often used as original equipment. Before purchasing, ensure compatibility with your vehicle. NGK, the world's leading OEM spark plug supplier, guarantees quality and reliability. This pack includes 8 spark plugs to keep your engine running smoothly.

What We Like
Performance & Longevity
Original Equipment
Quality & Reliability

ACDelco Iridium Spark Plug

41-162
1 Count (Pack of 1)
ACDelco Iridium Spark Plug Cover
ACDelco GM Original Equipment 41-162 (19417055) Iridium Spark Plug

The ACDelco GM Original Equipment 41-162 Iridium Spark Plug features an iridium composition that provides high melting point and great strength, resulting in excellent wear resistance and durability. The spark plug offers reliable cold starting, quick acceleration, smooth performance, and excellent engine idle stability. The three-piece fired in suppressor seal meters spark energy for long electrode life, prevents combustion leakage, and blocks radio frequencies that can affect vehicle electronics. ACDelco GM Original Equipment parts are designed, engineered, and tested to rigorous standards for Chevrolet, Buick, GMC, or Cadillac vehicles.

What We Like
Durable and long-lasting
Reliable cold starting and quick acceleration
Excellent engine idle stability and smooth performance
Buying Guide Image

Finding the Best Iridium Spark Plugs to Meet Your Car's Needs

Introduction

Iridium spark plugs are known for their high performance and durability, making them a popular choice among car enthusiasts and mechanics alike. But with so many different brands and options available, choosing the right iridium spark plugs for your vehicle can be a daunting task. In this article, we'll go over some key factors to consider when selecting iridium spark plugs, as well as some tips for installation and maintenance.

Factors to Consider

One of the first things to consider when choosing iridium spark plugs is the type of vehicle you have. Iridium spark plugs are available in a variety of sizes and thread pitches, so it's important to make sure you get the right ones for your engine. In addition to size, you'll also want to consider the heat range of the spark plugs. The heat range refers to how hot or cold the spark plug is, and it's important to choose the right heat range for your vehicle to prevent engine damage.

Another factor to consider is the brand of spark plug you choose. While there are many different brands of iridium spark plugs available, some are known for their durability and longevity, while others may not be as reliable. It's a good idea to do some research and read reviews to find out which brands have a good reputation among mechanics and car enthusiasts.

Installation and Maintenance

Once you've chosen the right iridium spark plugs for your vehicle, it's important to properly install them. This typically involves removing the old spark plugs and cleaning the spark plug wells before installing the new ones. It's a good idea to use a torque wrench to tighten the spark plugs to the recommended torque specifications, as over-tightening or under-tightling can cause problems.

In addition to proper installation, regular maintenance is also important for keeping your iridium spark plugs in good condition. This typically involves checking and replacing the spark plugs every 30,000 to 50,000 miles, depending on the vehicle and the type of spark plug you're using. It's also a good idea to regularly check the spark plug gaps to make sure they're properly set.

Conclusion

In conclusion, choosing the right iridium spark plugs for your vehicle is important for ensuring optimal performance and longevity. Consider factors such as the type of vehicle, the heat range, and the brand of spark plug, and make sure to properly install and maintain them for the best results. With the right iridium spark plugs, you can enjoy improved performance and peace of mind on the road.

Frequently Asked Questions (FAQs)

1. Do iridium spark plugs really make a difference?

Yes, iridium spark plugs make a significant difference in performance. They have better ignition capabilities, resulting in improved air-fuel compression within the combustion chamber. Additionally, iridium spark plugs have a longer lifespan compared to platinum spark plugs, typically lasting over 100,000 to 120,000 miles.

2. What are the disadvantages of iridium spark plugs?

While iridium spark plugs offer many advantages, there are a few disadvantages. Cheaper models may have only one thin layer of iridium, which can be prone to cracks and impact damage. To ensure the best results, it is recommended to invest in double or triple coated iridium spark plugs.

3. What's so special about iridium spark plugs?

Iridium spark plugs are special because iridium is an extremely durable metallic element with a high melting point. This makes it an excellent material for spark plugs. They offer complete combustion and better overall performance compared to other spark plug materials.

4. How often should iridium spark plugs be changed?

Iridium spark plugs tend to last longer than standard copper and nickel spark plugs. They can be changed every 60,000 to 150,000 miles, depending on the manufacturer's recommendations. It is always best to follow the specific guidelines provided by the spark plug manufacturer.

5. Can any car use iridium spark plugs?

Most cars that use copper spark plugs can be upgraded to iridium spark plugs. However, it is important to ensure that the iridium plugs are the correct size, voltage, and heat range for your specific engine. Always use spark plugs that are compatible with your car's engine.

6. Do iridium spark plugs improve gas mileage?

Yes, switching to iridium spark plugs can improve the gas mileage of gasoline vehicles, especially on the highway. The improved ignition profile of iridium spark plugs ensures more efficient burning of the fuel, resulting in better mileage.

Editor's Notes

During our iridium spark plug research, we found 24 iridium spark plug products and shortlisted 10 quality products. We collected and analyzed 60,862 customer reviews through our big data system to write the iridium spark plugs list. We found that most customers choose iridium spark plugs with an average price of $32.84.

The iridium spark plugs are available for purchase. We have researched hundreds of brands and picked the top brands of iridium spark plugs, including NGK, Autolite, Bosch, ACDelco. The seller of top 1 product has received honest feedback from 25,518 consumers with an average rating of 4.9.

Written by
Robert Reyes Avatar

Robert Reyes is a dedicated writer from San Francisco with a bachelor of degree in mechanics and a bachelor of degree in marketing. He focuses on making some complicated topics simple and enjoys explaining complex and technical things in an easy-to-understand way.