HKS Super Fire Racing Spark Plug - M40X (50003-M40X)

Optimize your ignition with the HKS M40X Super Fire Racing Spark Plug, the premium choice for high-performance tuning. This X Type plug is engineered with an NGK Heat Range 8 equivalent, providing superior heat dissipation and spark stability for engines running increased boost or high-compression setups.

The M40X is designed to withstand extreme cylinder pressures where standard plugs fail, making it a favorite for modified Suzuki K6A turbo engines and specific European performance applications.

Key Performance Benefits

• X Type Special Fitment: Features a $12\\text{mm}$ thread and $19\\text{mm}$ reach, specifically designed for specialized cylinder head geometries.

• 0.6mm Iridium Alloy Center Electrode: Lowers the required ignition voltage, ensuring a stronger, more consistent spark even under lean-burn or high-boost conditions.

• Platinum Ground Electrode: A square platinum chip provides extreme durability, maintaining the precise spark gap longer than standard performance plugs.

• Anti-Vibration Design: The shortened outer electrode reduces weight and resists high-frequency vibrations common in high-RPM racing environments.

• Self-Cleaning Thermal Edge: The ceramic insulator features a "Thermal Edge" that discharges to help burn off carbon deposits, preventing misfires after long periods of idling or cold starts.

Technical Specifications

• Part Number: 50003-M40X

• Plug Type: X Type

• Heat Range: NGK #8 Equivalent

• Thread Size: $12\\text{mm} \\times 19.0\\text{mm}$

• Wrench Size: $16\\text{mm}$

• Electrode: Iridium Center / Platinum Ground

Vehicle Compatibility

The HKS M40X is a specialty plug often used in:

• Suzuki: Every & Jimny (K6A DOHC Turbo - DA62W/DA62V), Cappuccino (EA11R/EA21R)

• European Models: Select BMW, Volkswagen, and Audi engines (2001–2007) that require a 12mm thread with a standard reach.

• Custom Builds: Ideal for small-displacement turbo engines requiring a colder heat range for track or spirited driving.

Purchasing Note: All HKS spark plugs are sold individually in Australia. Please ensure you select the correct quantity for your engine (e.g., Qty: 3 for Suzuki K6A, Qty: 4 for VW/Audi).