NGK Iridium IX CPR7EAIX-9 Spark Plug — 10.0 mm Thread, 0.6 mm Iridium Electrode, 5 kΩ Resistor

The NGK CPR7EAIX-9 Iridium IX spark plug is a high-performance replacement plug featuring an ultra-fine 0.6 mm iridium center electrode for improved ignition and long-lasting durability.

Designed as part of NGK's Iridium IX line, this plug combines a hardened iridium core with precisely engineered geometry to deliver consistent spark delivery across a wide range of engines. It is built with a 10.0 mm outer thread, 19 mm thread length, a 3 mm spark position and comes with a gasket seat and 5 kOhm interference suppression. The 16 mm spanner size makes installation straightforward for most workshop tools.

How does the iridium center electrode improve ignition performance?

The iridium center electrode is significantly harder and stronger than many conventional materials, allowing manufacturers to reduce the electrode diameter without sacrificing wear resistance. A finer electrode produces a more concentrated spark, helping with reliable combustion across operating conditions without altering engine hardware.

• 0.6 mm ultra-fine iridium center electrode for focused spark
• Durable iridium material resists erosion and maintains gap integrity
• Improved ignition consistency at varying RPM and loads
• Designed to fit standard ignition systems without modifications

What are the physical specifications I should check before buying?

Confirming the plug’s thread size, length and seat type ensures a proper fit and safe operation. The CPR7EAIX-9 has a 10.0 mm outer thread, 19 mm thread length and a gasket seat — match these to your engine’s requirements and verify the 16 mm spanner size for installation access.

• Outer thread: 10.0 mm
• Thread length: 19 mm
• Spark position (projection): 3 mm
• Spanner size: 16 mm and gasket seat type

Will this spark plug reduce electrical interference or affect ignition systems?

This model includes a 5 kΩ resistor for interference suppression to help limit electromagnetic noise affecting radios and electronic systems. It is compatible with most conventional and modern ignition systems, but always consult your vehicle’s service information to confirm compatibility with coil-on-plug or aftermarket ignition components.

• 5 kΩ integrated resistor for radio and electronics protection
• Single earthed electrode configuration for proven spark path
• Works with standard OEM-type ignition systems when matched correctly
• No engine reprogramming required for direct-fit replacements in approved applications

How should I install and maintain these plugs for best results?

Install with the correct torque and ensure the gasket seat seats flat to avoid compression leaks. Check and set the electrode gap only if your vehicle manual specifies a particular gap; otherwise, leave factory gap intact. Periodic inspection during routine service will reveal electrode wear or fouling if present.

• Use a 16 mm socket and torque to the vehicle manufacturer’s specification
• Do not overtighten—secure gasket seat for proper sealing
• Replace per manufacturer interval or when signs of wear appear
• Keep factory gap unless a specific gap is required by your engine

Who is this for: The NGK CPR7EAIX-9 is intended for vehicle owners, mechanics and performance-minded drivers seeking a reliable direct-fit iridium replacement plug. It suits applications that require a 10.0 mm thread with a 19 mm reach and a gasket seat, and for anyone wanting long-lasting electrode life and interference suppression without changing ignition hardware.