Unlock extreme performance and ignition reliability with the HKS M45i Super Fire Racing Spark Plug. As an ISO Type performance plug with an NGK Heat Range 9 equivalent, the M45i is engineered specifically for high-boost, high-compression, or track-focused engines where managing intense cylinder heat is the difference between power and engine failure.
Designed as a "colder" plug, it dissipates heat faster than standard units, providing a massive safety margin against pre-ignition and detonation (knock) in heavily tuned vehicles.
Cold Heat Range (NGK #9): The ultimate thermal protection for aggressive ECU tunes, upgraded turbochargers, or nitrous applications.
0.6mm Iridium Alloy Center Electrode: Drastically lowers the required ignition voltage, ensuring a lightning-fast, powerful spark even under extreme cylinder pressures.
Platinum Ground Electrode: Features a specialized square platinum chip that significantly increases durability and maintains a precise spark gap over time.
Anti-Vibration Short Tip: The outer electrode is shortened and tapered to reduce weight and withstand the high-frequency vibrations of high-RPM racing.
Thermal Edge Technology: Signature HKS ceramic insulator design helps discharge carbon buildup, preventing misfires during extended idling or stop-start driving.
| Attribute | Detail |
| HKS SKU | 50003-M45i |
| Plug Type | ISO Type (M-i Series) |
| Heat Range | NGK #9 Equivalent (Cold) |
| Thread Size | $14\text{mm} \times 19.0\text{mm}$ |
| Wrench Size | $16\text{mm}$ |
| Electrode | Iridium Center / Platinum Ground |
The HKS M45i is a high-performance ISO fitment popular for:
Nissan: Skyline R32/R33/R34 (RB20/25/26DET), Silvia S13/S14/S15 (SR20DET), Stagea (RB25)
Toyota: Supra (JZA80), Chaser (JZX100), Aristo (2JZ-GTE)
Honda: Integra Type R (DC2/DC5), S2000 (F20C/F22C), Civic Type R (EK9/EP3)
European Models: Highly popular as a colder upgrade for tuned Audi 1.8T/2.0TSI, BMW M-Series (select models), and VW Golf GTI/R builds.
Purchasing Note: Spark plugs are sold individually in Australia. For a 6-cylinder engine (Skyline/Supra/M-Series), please order Quantity: 6. For a 4-cylinder engine (Silvia/Evo/VAG), please order Quantity: 4.
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