- R35 GT-R stock's heat range is the same as NGK 8, NGK 9 to 86/BRZ, and the new HKS M50HL is the same as NGK 10. It's for a high tuning vehicles.
- Reinforced by making the outer electrode bigger(see the pictures below). Also could have a steady ignition and ignition speed at a high load and high RPM by putting the center electrode in the middle of the spark plug.
- Improved the anti-taint property by making thermal edge to prevent the carbon buildup which occurs for the tuned engines
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