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HKS M-Series Super Fire Racing spark plugs are high performance Iridium plugs designed to handle advanced levels of tuning and provide Improved ignition performance, durability and anti-carbon build-up

M-Series Super Fire Spark Plugs Feature:

1. 0.6mm Iridium Alloy Center Electrode
   Iridium Alloy Center Electrode reduces voltage requirement as well as improving ignition performance and durability.
2. Outer Electrode with Platinum Chip
   The Outer Electrode incorporates a square platinum chip which improves durability, and when combined with the iridium center electrode boosts ignition performance.
3. 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.
4. Thermal Edge
   After long idling or various combustion conditions carbon buildup can occur causing misfires. The Thermal Edge of the ceramic insulator will discharge to help decrease carbon deposits.
5. Spark Support Gap
   Discharges will occur in the Spark Support Gap (space between the tip of insulator and the base of the outer electrode) to help prevent carbon buildup.
   

*M Series is recommended for reliable ignition, durability and anti-carbon buildup under high load.

The Iridium alloy is used because of its durability and reliability.  On an average plug, a narrow core typically shortens life span of plug but with the intense durability of iridium there is no sacrifice in any longevity.  With a high melting point of 2454 degrees C, opposed to the 1769 degrees C of white gold, the electrode can tolerate the high levels of compression and minor knocking without any deterioration. A nickel coating on the housing also prevents the spark plug from premature deterioration.  The Iridium plugs are available for multiple applications and offered in “colder” heat ranges of 7 and up and specifically for rotary, heat ranges of 9 and up are offered.

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 just for reference.