NGK Iridium IX Spark Plugs Subaru WRX (GD / GE / GH) / WRX STI (GD / GR / GV / VA) / Mitsubishi Lancer Evolution IX (CT9A) Heat Range 7

The NGK LFR7AIX Iridium IX Spark Plug is engineered for high-performance and modified engines, offering exceptional ignitability, improved throttle response, and long-lasting durability. Ideal for enthusiasts and tuners, it delivers consistent spark in demanding conditions.

Key Features:

• Thread Size: 14mm diameter x 1.25mm pitch

• Reach: 26.5mm (1.04")

• Hex Size: 16mm (5/8")

• Seat Type: Gasket

• Terminal Type: Solid

• Gap: 0.8mm (0.031")

• Centre Electrode: Fine wire iridium, 0.6mm

• Ground Electrode: Standard nickel, taper cut

• Projection: Projected tip for better combustion

• Heat Range: 7 (NGK scale)

• Resistor: Yes – 5k Ohm interference suppression

• Torque Specs:

  • Cast Iron Head: 18–25.3 lb. ft.

  • Aluminium Head: 18–21.6 lb. ft.

Additional Details:

• Brand: NGK / NTK

• Longevity: Up to 80,000km

• Warranty: 60 days

Whether you're upgrading a turbocharged engine or replacing OEM plugs with performance alternatives, the NGK LFR7AIX offers reliable ignition and a longer service life under high-stress conditions.

NGK stock number: 2309 replaces part number LFR7AIX on our listings. It is the same plug: NGK prints the part number (LFR7AIX) on the plug and both numbers on the box.