NGK 91784 Spark Plug

Reliable Ignition Performance for Infiniti, Lexus, Nissan, and Toyota

The NGK Ruthenium HX High Ignitability Spark Plug (part number 91784) is engineered to deliver consistent ignition and improved combustion efficiency. Designed for select Infiniti, Lexus, Nissan, and Toyota models, this spark plug supports optimal engine performance and fuel economy.

• Projected square platinum ground electrode for high ignitability
• Ruthenium center electrode tip for enhanced durability and stable spark
• Copper core materials in both center and ground electrodes for efficient heat dissipation
• Standard ground configuration with a single ground electrode
• Non-removable nut electrical terminal type for secure connection
• Pre-gap size of 0.032 inches for precise spark gap
• Flat seat type with 26.5 mm reach and 12 mm thread diameter
• Hex size of 14 mm for installation with common tools
• Manufacturer heat range rating of 8 suitable for specified vehicle applications

About the Ruthenium HX High Ignitability Spark Plug Line

The NGK Ruthenium HX High Ignitability Spark Plug line focuses on delivering improved ignition performance through advanced electrode design. Featuring a ruthenium center electrode tip combined with a projected square platinum ground electrode, this product line enhances ignitability and combustion stability. The 91784 spark plug benefits from these design elements to provide reliable starts and efficient engine operation in compatible vehicles.

Technical Details and Application

This spark plug incorporates copper core materials in both the center and ground electrodes, which aid in effective heat transfer and durability. The projected square platinum ground electrode tip is designed to improve ignitability, reducing misfires and promoting smoother engine running. With a pre-gap size of 0.032 inches and a flat seat type, the NGK 91784 spark plug fits securely and maintains consistent spark gap over time. Its heat range of 8 is matched to the thermal requirements of various Infiniti, Lexus, Nissan, and Toyota models, including the 370Z, FX37, G37, GT-R, LS500, LX600, Q50, Q60, Sequoia, and Tundra.

Compatible Vehicles and Common Applications

• Improves ignition reliability in Infiniti 370Z, Q50, and Q60 models
• Supports efficient combustion in Lexus LS500, LX600, and GX550
• Enhances spark stability for Nissan GT-R, FX37, and G37 engines
• Optimizes performance in Toyota Sequoia and Tundra vehicles
• Reduces misfire and rough idle issues in compatible models

Installation Notes and Tips

When installing the NGK 91784 spark plug, ensure the spark plug gap is set to the specified pre-gap of 0.032 inches if adjustment is necessary. Use a 14 mm socket wrench for proper tightening to avoid damage to the flat seat threads. The non-removable nut electrical terminal type requires compatible ignition wiring connectors. Always follow manufacturer torque specifications and engine service guidelines for best results.

Quality Assurance and Warranty

NGK spark plugs, including the Ruthenium HX High Ignitability Spark Plug 91784, are manufactured to meet strict quality standards for durability and performance. The use of copper core electrodes and precious metal tips ensures long service life and consistent ignition. Warranty coverage details should be confirmed with the vehicle manufacturer or authorized NGK distributor.