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HKS M45HL Super Fire Racing Spark Plugs

Ignitionability, durability, anti-insulation are all reinforced. HKS has made the best plug for both tuning engines and stock engines.


  • 0.6mm Iridium Alloy Center Electrode
    Iridium alloy center electrode reduces voltage requirement and improves ignition performance and durability.
  • Outer Electrode with Platinum Chip
    The outer electrode incorporates a square platinum chip which improves durability, and combining with the iridium center electrode boosts ignition performance.
    The outer electrode features a shortened tip design and tapered shape while maintaining the necessary space for proper ignition.
  • Short Type Outer Electrode (Anti-Vibration)
    The outer electrode has been shortened and engineered with the ideal shape to decrease weight for resistance against vibration. This anti-vibration design improves longevity of the outer electrode.
  • Thermal Edge
    After long idling or under various combustion conditions, carbon buildup can occur causing misfires. The thermal edge of the ceramic insulator discharges to help decrease carbon deposits.
  • Spark Support Gap
    Discharge occurs in the spark support gap (space between the tip of insulator and the base of the outer electrode) to help prevent carbon buildup.


    Performance and Efficiency

    • Increased Ignition Performance
      Decreased voltage requirement strengthens ignition performance under harsh conditions like lean mixture or high boost pressure.
    • Improved Durability
      New material and design improve durability which allows for use under hard combustion conditions like continuous high load during circuit driving or aggressive tuning.
      * Improper combustion condition and wrong heat range selection may cause damage to the spark plug.
    • Decreased Carbon Deposits
      Thermal edge and spark support gap help prevent carbon buildup for better ignition under various combustion conditions.


      ■Heat Range Conversion Chart

      HKS 25 30 35 40 45 50 52.5 55
      DENSO 16 20 22 24 27 31 32 34
      NGK 5 6 7 8 9 10 10.5 11

      * Above information is the reference for heat resistance.