NGK SILZKBR8D8S Iridium Spark Plug for BMW 2, 3, 4, and 5 Series, X1, X3, X4, X5, Z4, and Alpina (2012–2019)

NGK 97506, designation SILZKBR8D8S, is an iridium-tipped spark plug for a wide range of 2012–2019 BMW models, from the 228i and 328i to the X5 and Alpina B7. The center electrode has a copper core with an iridium tip. The single ground electrode also has a copper core and uses NGK's square platinum electrode (SPE) tip design. The 12 x 1.25 mm thread has a 26.5 mm reach and a flat seat, and the insulator stands 50 mm tall. NGK rates it at heat range 8, with a 5,000-ohm resistor and a non-removable terminal nut. It is made in Japan.

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

The SILZKBR8D8S cross-references to three BMW OE numbers: 12120039664, 12120038896, and 12120038704. Matching any of these to your service records or to the old plug confirms you have the right part. A 14 mm 12-point bi-hex replaces the usual six-point hex, so a standard plug socket will not fit. BMW tool 83300495560 is the matching socket. The plug comes pre-gapped at 0.030 in (0.762 mm), and that gap is correct for OE applications. Fuel and oil deposits on the electrode over many ignition cycles are what eventually wear a plug out.

Technical Details

• Manufacturer: NGK, a brand of Niterra Co., Ltd., Nagoya, Japan
• NGK part number: 97506, designation SILZKBR8D8S
• OE references: BMW 12120039664, 12120038896, and 12120038704
• Thread: 12 x 1.25 mm; reach: 26.5 mm; flat seat
• Hex: 14 mm bi-hex (12 point)
• Electrodes: copper-core iridium center, copper-core ground with SPE tip, one ground
• Heat range 8; 5,000-ohm resistor
• Insulator height: 50 mm; non-removable terminal nut
• Made in Japan
• Warranty: 24 months / 24,000 miles

Installation & Tuning Notes

Tighten to 23 ± 3 Nm (about 17 ft-lb) using the 14 mm 12-point socket. For N54, N55, B58, and S55 engines, reset the gap from the preset 0.762 mm to 0.56 mm (0.022 in). On turbocharged engines, check your engine code before installing.

Common Questions

Can I use my regular spark plug socket?
No. This plug has a 14 mm 12-point bi-hex, and BMW tool 83300495560 is the socket made for it.

Do I need to re-gap it?
The 0.762 mm preset suits OE applications. N54, N55, B58, and S55 engines call for 0.56 mm.

Fitment & Compatibility

Check the fitment table below for each BMW and Alpina model this plug covers. Confirm your engine code, since it determines the gap setting. Send us your VIN and we will verify fit.