SKU: 50003-M45I-1 HKS Super Fire Racing Spark Plug M45i Single The HKS 50003-M45I-1 Super Fire Racing Spark Plug is a high-performance iridium spark plug engineered for maximum ignition efficiency and durability in high-boost, high-RPM, or tuned engines. Featuring a 0.6mm ultra-fine iridium center electrode and a platinum ground electrode, this plug delivers superior ignitability, faster flame kernel growth, and better combustion under extreme conditions. The heat range M45i (comparable to NGK 8-9) is optimized for naturally aspirated or mildly boosted applications, while the special insulator and electrode design resist pre-ignition and fouling. Sold individually, the Super Fire Racing plug is ideal for Honda, Nissan, Mitsubishi, Subaru, and other performance vehicles seeking improved throttle response, smoother idle, and higher power potential. Perfect for street, track, or drift builds where reliable ignition is critical. Key Features & Benefits 0.6mm Iridium Center Electrode Ultra-fine tip for superior ignitability and spark focus Platinum Ground Electrode Enhanced durability and consistent performance under high heat Heat Range M45i Balanced for naturally aspirated or mild boost; resists pre-ignition Special Insulator Design Improves thermal conductivity and reduces fouling HKS Engineering Japanese precision for maximum combustion efficiency and power Specifications Specification Detail Part Number 50003-M45I-1 Brand HKS Thread Diameter M14 x 1.25 Reach 26.5mm (long reach) Hex Size 16mm Heat Range M45i (equivalent to NGK 8-9) Electrode 0.6mm iridium center / platinum ground Gap Pre-gapped (confirm with engine specs) Quantity Single plug Whats Included One HKS Super Fire Racing spark plug (M45i) Product Notes Single plug order quantity needed for full set (typically 4, 6, 8 depending on engine) Optimized for high-RPM, boosted, or tuned engines excellent ignitability Resists fouling and pre-ignition under high boost or aggressive timing Compatible with stock or aftermarket ignition coils HKS legendary Japanese brand for performance ignition and engine components Installation Notes Estimated time: 30-60 minutes (full set) Remove old spark plugs, clean threads Install HKS Super Fire plugs with anti-seize (if recommended), torque to spec (typically 18-22 ft-lbs) Check gap if adjusting (pre-gapped from factory) Professional installation recommended for high-performance builds This Part Fits Year Range Make Model Engine Notes Universal (M45i heat range) Universal Universal Universal M14 x 1.25 thread, 26.5mm reach confirm engine specs and heat range Why Choose HKS Super Fire Racing Spark Plugs? Ultra-fine iridium electrode for superior ignitability and combustion efficiency High heat range tolerance for boosted or high-RPM applications Reduced fouling and longer life compared to stock plugs Frequently Asked Questions Q: Is this plug for a specific engine? A: M45i heat range suits many naturally aspirated or mildly boosted engines; confirm with engine builder. Q: How many plugs do I need? A: One per cylinder order quantity needed for your engine (e.g., 4, 6, 8). Q: Do I need to regap them? A: Pre-gapped from factory; adjust only if engine builder recommends specific gap. Shipping and Handling Method: UPS / FedEx Ground Availability: In stock ships same or next business day Packaging: Secure protective packaging Weight: Approx. 0.5-1 lb (single plug) Reviews There are no reviews yet. Be the first to review “HKS Super Fire Racing M45i Spark Plug Single” Cancel replyYour email address will not be published. Required fields are marked *Your rating * Rate… Perfect Good Average Not that bad Very poor Your review *Name * Email * Save my name, email, and website in this browser for the next time I comment.
