NGK Spark Plug Stock # 7781

The NGK Spark Plug Stock # 7781 is a precision-engineered ignition component designed for drivers and mechanics who demand reliable combustion performance across a wide range of automotive applications. This spark plug serves as a direct replacement for original equipment specifications, ensuring proper gap, heat range, and electrical conductivity without compromise.

NGK's ZFR5LP-13G designation indicates a standard-reach plug with a 13mm thread size and a carefully calibrated heat range suitable for stock engines. The premium ceramic insulator and nickel-alloy electrode design provide superior thermal transfer and extended service intervals compared to conventional copper-core alternatives. This construction resists fouling, pre-ignition, and electrode erosion, which are critical factors when troubleshooting engine performance issues.

Technicians and enthusiasts rely on this plug when performing routine maintenance, engine rebuilds, or fuel system upgrades that require verified OEM-spec ignition components. Installation is straightforward—confirm the 13mm thread size and proper reach before seating to avoid cross-threading or improper contact in the combustion chamber. Whether you're restoring a classic vehicle or maintaining a daily driver, the NGK Spark Plug Stock # 7781 is an essential component for optimal engine performance.