Key Features of Premium Performance Spark PlugsUltra-Fine Electrodes: Plugs like the HKS Super Fire Racing series utilize ultra-fine [0.6mm] iridium or platinum centers. This highly concentrated spark promotes a stronger, more complete burn.Reduced Electrical Demand: Smaller electrodes require less voltage to jump the spark gap, which minimizes engine misfires and ensures a smoother idle.Enhanced Durability: Precious metals like iridium resist high-temperature melting and spark erosion, granting a longer service life