NGK Iridium SILZKBR8D8S spark plug, also known as the "97506" plug, for tuned S55 and S63 engines. Required with Stage 2 and above packages on S55, and similar modification levels on S63.
Priced individually, recommend replacement every 30K. Six required for S55, eight required for S63.
Vehicles Supported
BMW F87 M2 Competition
BMW F8X M3/M4
BMW F10 M5
BMW F12/F12/F06 M6
BMW F85/F86 X5M/X6M