HKS 50003-M40iL M-Series Super Fire Racing Iridium Spark Plug

The HKS 50003-M40iL is a high-performance M-Series Super Fire Racing spark plug featuring advanced iridium alloy construction for exceptional ignition performance, durability, and anti-carbon buildup. Engineered for heavily modified and high-load applications, this plug delivers reliable ignition even under extreme conditions.

Key Features:

• 0.6mm Iridium Alloy Center Electrode: Ultra-fine electrode ensures focused spark energy and improved combustion efficiency
• Platinum Chip Outer Electrode: Enhanced durability and resistance to electrode wear
• Short Type Outer Electrode: Anti-vibration design for stability in high-RPM applications
• Thermal Edge Technology: Optimized heat dissipation prevents pre-ignition and fouling
• Spark Support Gap: Ensures consistent spark performance across all operating conditions
• High-Temperature Resistant: Iridium's 2454°C melting point withstands extreme compression and minor detonation
• Nickel-Coated Housing: Prevents corrosion and premature deterioration

The M-Series is specifically designed for heavily tuned engines operating under high boost, elevated compression ratios, and demanding track conditions. The iridium alloy construction maintains electrode integrity far longer than conventional spark plugs, while the platinum outer electrode ensures consistent spark gap over extended service intervals.

Note: Sold individually. M-Series plugs are available in colder heat ranges (7 and up) for forced induction and high-compression applications, with heat ranges 9 and up offered specifically for rotary engines.