NGK 91874 Spark Plug

NGK Laser Iridium Spark Plug for BMW and Rolls-Royce

NGK 91874 is a Laser Iridium High Ignitability spark plug built for select BMW and Rolls-Royce applications. It combines an iridium center electrode tip with a square platinum ground electrode tip design to support consistent ignition performance, stable combustion, and OE-style serviceability.

For drivers searching for a BMW 750i spark plug, BMW X5 spark plug, or Rolls-Royce Ghost spark plug replacement, this NGK part number 91874 is listed for multiple 2008-2015 applications with a 0.032 in. gap specification in the fitment notes.

Key Features

• Laser Iridium High Ignitability design for precise spark delivery
• Iridium center electrode tip material for durability and ignition consistency
• Square platinum ground electrode tip design
• Resistor type spark plug with 5000 resistance
• Pre-gapped at .030 with fitment notes calling for 0.032 in. gap on listed vehicles
• 12 mm thread diameter, 14 bi-hex hex size, flat seat
• OE-style construction for select BMW and Rolls-Royce engines

Product Details

NGK is a long-standing OE supplier with broad coverage across domestic and import vehicles, and the Laser Iridium High Ignitability line is positioned for applications that require precise ignition control and original-equipment-style fit. Part number 91874 uses an iridium center electrode, nickel ground electrode core material, and a copper center electrode core to support reliable spark performance under demanding engine conditions. This part cross-references NGK 91874 for the same application.

Compatible With select 2008-2015 BMW 550i, 550i xDrive, 550i GT, 550i GT xDrive, 650i, 650i xDrive, 750i, 750i xDrive, 750Li, 750Li xDrive, 760Li, X5, and X6 models, plus 2011-2013 Rolls-Royce Ghost applications listed in the fitment data. Search terms such as BMW 750Li xDrive spark plug replacement, BMW X6 ignition service part, and Rolls-Royce Ghost NGK 91874 are directly aligned with this listing.

Common Uses

• Misfire diagnosis tied to worn spark plugs
• Hard starting caused by weak ignition output
• Rough idle from degraded plug electrodes
• Reduced throttle response from inconsistent combustion
• Scheduled ignition service on listed BMW and Rolls-Royce engines

Installation Notes

Verify engine code and application before installation. The fitment notes specify a 0.032 in. gap for the listed vehicles, so confirm and adjust the gap as required before use. Use the correct torque procedure for the cylinder head material and inspect ignition coils, boots, and seals during service. For BMW 750i, BMW X5, and Rolls-Royce Ghost applications, follow the vehicle service information for plug access and replacement intervals.

Quality Assurance

NGK manufactures spark plugs to OE standards and supplies ignition components for a wide range of automotive applications. Part number 91874 reflects that OE-focused engineering approach for select BMW and Rolls-Royce fitments.