HKS M-Series Super Fire Racing spark plugs are sold individually. These high performance iridium plugs are designed to handle higher boost with improved ignition performance and anti-carbon build-up. Fits 90’s Integra, Civic, CRX, Prelude, 180SX, 300ZX, R32, R33, R34 Skyline, MR2, 7MGTE Supra… Please double confirm fitment with your vehicle before purchase!

Known Vehicle Fitments:
1991-1993 Acura Integra B18A1/DB1
1992-1996 Honda Civic D15B7/EY4
1987-1991 Honda Civic D15B2/EF2/EF4
1987-1991 Honda CRX D15B2/EF6
1985-1991 Honda Prelude B20A5/BA1/BA4/BA5
1989-1991 Nissan 180SX CA18DET/RS13/KRS13
1984-1989 Nissan 300ZX VG30T/HZ31/HGZ31
1989-2002 Nissan Skyline RB26DETT/BNR32/BNR33/BNR34
1991-1993 Nissan Skyline RB25DE/ECR32/ER32
1989-1991 Nissan Skyline RB20DE/HR32/HCR32/HNR32
1989-1991 Nissan Skyline RB20DET/HCR32/HNR32
1988-1989 Toyota Celica 3S-GTE/ST165
1987-1989 Toyota Celica 3S-GELC/ST162
1984-1989 Toyota MR2 4A-GELC/AW11
1987-1992 Toyota Supra 7M-GTE/MA70

Includes:
(1) Spark Plug
Spark plugs are sold individually price is for one plug!

Heat Range and Thread

HKS Plug Heat Range Conversion Chart

0.6mm Iridium Alloy Center Electrode:
Iridium Alloy Center Electrode reduces voltage requirement as well as improving ignition performance and durability.

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.

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 various combustion conditions carbon buildup can occur causing misfires. The Thermal Edge of the ceramic insulator will discharge to help decrease carbon deposits.

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°C, opposed to the 1769°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