HKS M-Series Spark Plugs

(23 customer reviews)


145 items sold



Ultimate spark plug “M”.

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


* Above information is the reference for heat resistance.

Additional information

Weight1 lbs
Dimensions4 × 2 × 2 in

23 reviews for HKS M-Series Spark Plugs

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  1. David Chung (verified owner)

    Plugs got here fast!

  2. Jean M. (verified owner)

    Great price and fast shipping!

  3. Anonymous (verified owner)

    Exactly what I needed and product came fast from the other side of the country

  4. Yeng Lor (verified owner)

    Fast shipping can’t wait to order more off kdtuners

  5. BEN WAXMAN (verified owner)

    plugs worked as expected

  6. Andrew Osmond (verified owner)

    Super fast shipping. Everything packaged well and secure. I will be purchasing more things from kdm tuners!

  7. justin sexton (verified owner)

    Best price around for the plugs and quick shipping.

  8. Francisco Caban (verified owner)

    Exelent seller, exelent sparks plugs recommended 100%

  9. Anonymous (verified owner)


  10. Christopher Mayo (verified owner)

    Josh and KDM was very helpful and accomodating to make sure I got my plugs ASAP. They even went out there way on the weekend to ensure I would get it by end of Sunday! From now on I will be making all available purchases for my VT with KDM.

  11. jeffrey h. (verified owner)

    Fast shipping. Messaged me after I asked a question. 10/10

  12. Martin P. (verified owner)

    Great product

  13. Stephen Surita (verified owner)

    Great price

  14. Carlos T. (verified owner)

    Fast shipping best prices

  15. christopher fox (verified owner)

    Excellent service!! Now if only they’d send me a cylinder head lol

  16. Ross C. (verified owner)

    This company is incredible! Super quick updates and fast order processing. Will definitely be back!

  17. Mark Cook (verified owner)

    Best deal I had found on a genuine product. Thank you guys for more than reliable service. A product that exceeds my expectations.

  18. Anonymous (verified owner)

    Super gast delivery!

  19. Quentin (verified owner)

    Packed well and shipped quickly, have yet to install but plugs seem to be in perfect condition.

  20. Mike D. (verified owner)

    Excellent price showed up quickly

  21. Axel (verified owner)

    Got probably the best deal on any website and I got them very fast. That’s why i like purchasing from here

  22. Kevin wilson (verified owner)

    You guys are the best with fast shipping

  23. Anonymous (verified owner)

    Quick install ready and fast shipping!

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