NGK Laser Iridium Spark Plug 97506 (SILZKBR8D8S) 4-Pack — Iridium Tip, OEM Fit for BMW

These Laser Iridium plugs combine a fine iridium center tip and a platinum ground tip on a copper core to deliver consistent ignition, extended service intervals, and reliable fitment where factory NGK plugs were specified. The 97506 (SILZKBR8D8S) is commonly used across multiple BMW 2-, 3-, 4-, 5-, X- and Z-series model years; check engine and drivetrain compatibility before ordering to ensure correct quantity and fit.

Which BMW models use the NGK 97506 plug?

These plugs are compatible with a broad range of BMW vehicles equipped with compatible engines from roughly 2012–2018. They are commonly fitted to entry-level turbocharged engines used in several 2-, 3-, 4-, 5-, X- and Z-series variants.

• 228i (2014–2016) and 228i xDrive (2015–2016)
• 320i/320i xDrive (2012–2018), 328i/328i xDrive/GT xDrive (2012–2016)
• 428i series including Gran Coupe and xDrive variants (2014–2016)
• 528i (2012–2016), X1/X3/X4/X5 model ranges, and Z4 (various years listed)

How does the Laser Iridium design affect ignition performance?

NGK’s fine-wire iridium center electrode and square platinum ground tip reduce the voltage required to fire the plug, supporting easier starts and a more consistent spark under varied loads. The long-projection center electrode and fine-wire design focus the spark for stable ignition and smoother throttle response.

• Iridium center tip for high-temperature durability and lower wear
• Square Platinum Electrode (SPE) ground tip for improved ignitability
• Copper core center and ground electrode for rapid heat transfer
• Pre-gapped to 0.030 in (0.75 mm) to match OEM expectations

What are the key technical features and dimensions?

The 97506 plug is built to match OEM mechanical and electrical specs so it fits properly and performs reliably. It includes a resistor and ceramic insulator, a flat seat, and a 14mm bi-hex hex size for installation with common tools.

• Part number: SILZKBR8D8S / Stock: 97506; heat range 8
• Thread diameter 12.0 mm, reach 26.5 mm (1.043 in), flat seat
• Insulator height 51.0 mm, hex size 14 mm bi-hex, pre-gap 0.030 in
• Resistor-equipped, non-removable nut terminal, washer included

What should I know about lifespan and maintenance?

Iridium and platinum materials extend service life compared with standard copper plugs, but replacement intervals depend on driving conditions and engine tuning. Always follow your vehicle manufacturer’s maintenance schedule and inspect plugs for fouling, electrode wear, or damage when diagnosing misfires or performance issues.

• Iridium center and platinum ground extend useful life versus copper-only plugs
• Recommended to verify torque and electrode condition at service intervals
• Use correct quantity and proper gap; research engine-specific requirements before purchase

Who is this for: Owners and technicians who need direct-fit NGK OEM-equivalent spark plugs for compatible BMW engines seeking reliable starts, steady combustion, and longer replacement intervals. Ideal for routine maintenance, restorations to factory spec, or performance-minded drivers who prefer NGK’s Laser Iridium construction for longevity and stable ignition.