NGK Spark Plug Stock # 2309

The NGK Spark Plug Stock # 2309 (LFR7AIX) is a premium OEM-grade ignition component designed for drivers and mechanics who demand reliable engine performance and longevity. Whether you're rebuilding a tired engine, performing routine maintenance, or upgrading a stock ignition system, this iridium-core spark plug delivers the consistent firing voltage needed for efficient combustion across a wide range of engine speeds and loads. NGK's reputation in the automotive aftermarket and OEM sectors makes this plug a trusted choice for both daily drivers and enthusiasts alike.

At the technical level, the LFR7AIX features an iridium center electrode with a fine-wire design that concentrates spark energy more precisely than conventional copper-core plugs, resulting in faster flame kernel development and more complete fuel combustion. The tapered seat design ensures a gas-tight seal in the cylinder head, preventing exhaust blowby and maintaining optimal compression. With a compact profile (0.9 x 0.9 x 3.8 inches) and minimal weight (0.12 lbs), the plug integrates seamlessly into stock engine bays without requiring modifications or specialized tools—standard 3/4-inch socket removal and installation apply. Iridium's superior heat resistance also extends service intervals, reducing the frequency of plug changes over the vehicle's lifetime.

This NGK spark plug is ideal for mechanics performing scheduled maintenance, engine rebuilds, or performance tuning where baseline ignition quality matters. The LFR7AIX is engineered to fit a broad range of passenger vehicles and light trucks that call for a standard-reach, fine-wire iridium plug; always verify fitment against your vehicle's factory service manual or consult a trusted technician to confirm compatibility before purchase. Proper gap setting and installation torque (typically 18–22 ft-lbs depending on cylinder head material) ensure optimal performance and prevent thread stripping or fouling issues that can compromise engine response.