Dinan N20/N54/N55/S55/N63/S63 Iridium Spark Plug - Heat Range 9 - 12mm x 26.5mm x 14mm (HV) - SINGLE

The same iridium electrode and copper core construction as the B-series plug, sized for N-series BMW applications. Heat range 9 lands one step colder than OEM for N20, S55, N63, and S63; two steps colder for N55; and three steps colder for N54 — the differential reflects each engine's stock operating temperature and detonation resistance margin. Colder plugs transfer combustion heat faster from the chamber, which is exactly what tuned engines need under boost. Optimized electrode geometry fires reliably on ethanol blends. HV terminal (nut-style), flat seat, 12mm x 26.5mm, 14mm Bi-Hex, 0.5mm gap, 17 Nm install torque. Sold individually.

Features:

+ Iridium electrode — 152% higher MP than silver, 38% higher than platinum
+ Heat range 9: 1 step colder (N20/S55/N63/S63), 2 steps colder (N55), 3 steps colder (N54)
+ Projected insulator, optimized for ethanol and hard-to-ignite fuels
+ 12mm x 26.5mm thread, 14mm Bi-Hex, HV terminal, flat seat, 0.5mm gap, 17 Nm
+ Made in the EU — sold individually