HKS Super Fire Racing M40i Iridium Spark Plug (NGK 8, ISO) - Single

The HKS Super Fire Racing M40i is an ISO-type iridium spark plug with an NGK 8 equivalent heat range, built for tuned and stock performance engines. Its 0.6 mm iridium center electrode and platinum-chip outer electrode lower the required firing voltage for strong ignition under high boost or lean conditions, while the thermal edge and spark-support gap resist carbon fouling. This ISO seat fits a wide range of Japanese turbo and naturally aspirated engines (RB, SR, VG, and similar) calling for an ISO φ14 plug. Sold individually.

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