HKS SUPER FIRE RACING M45i

This is the HKS Super Fire Racing M45i spark plug, part number 50003-M45I. These plugs are built for performance applications, featuring a fine-tipped iridium center electrode for improved spark and combustion. The M45i designation indicates a specific heat range and thread size, designed to work with a variety of performance engines where a hotter spark is beneficial for power and efficiency.

HKS uses a unique ground electrode design with a center electrode that is 0.6mm fine-tipped iridium. This construction helps to reduce voltage requirement, leading to a more consistent and powerful spark. The plug's construction is well-built to handle the demands of higher compression and more aggressive engine tuning. They are often chosen by enthusiasts looking to get the most out of their engine's ignition system.