NGK SILZKGR8B8S Iridium Spark Plug for BMW 2/3/4/5/6/7 Series, X1–X4, and Mini Cooper (2014–2024)

Built for BMW and Mini turbocharged gasoline engines, the NGK SILZKGR8B8S (part 94201) is an iridium-tipped spark plug that fires the cylinders of models from the 2 Series through the 7 Series, the X1 to X4, and the Mini Cooper, Clubman, and Countryman. It pairs a copper-core center electrode with an iridium tip and a single platinum ground electrode with a taper-cut tip. NGK makes it in Japan at OE quality, and it cross-references to BMW numbers 12120040551 and 12120041666. The plug uses a 12x1.25mm thread, a 26.5mm reach, and a flat seat, with a 14mm 12-point hex instead of a conventional six-sided hex.

This NGK spark plug carries a 24-month or 24,000-mile warranty.

The 12-point hex is the detail most likely to catch out an owner at the bench, since a standard spark plug socket will not fit. NGK rates this plug at heat range 8 with a 5,000-ohm internal resistor, a cup-style terminal, and a 51mm insulator height. Deposits from fuel and oil build up on the electrodes over countless ignition cycles, and a worn plug brings reduced power, misfires, and poor fuel economy.

Technical Details

• Manufacturer: NGK; plug code SILZKGR8B8S, part 94201
• Cross-references: 12120040551, 12120041666
• Electrodes: copper core with iridium center tip; one platinum taper-cut ground
• Thread 12x1.25mm, reach 26.5mm, flat seat
• Hex: 14mm 12-point
• Heat range 8; resistor type, 5,000 ohms
• Insulator height 51mm; cup terminal
• Made in Japan
• Warranty: 24 months or 24,000 miles

Installation & Tuning Notes

NGK pre-gaps this plug at 0.030 in (0.76mm). Tighten to 23 ± 3 Nm, about 17 ft-lb.

Common Questions

Which socket do I need?
A 14mm 12-point spark plug socket.

Do I need to gap it?
It comes pre-gapped at 0.030 in (0.76mm).

PMB sells NGK plugs alongside a deep range of BMW and Mini maintenance parts.

Fitment & Compatibility

Check the fitment table below for your model, year, and trim. Send us your VIN and we will confirm fit.