NGK 2238 V-Power Spark Plugs TR5 From professional racers with extremely modified engines to the weekend warrior, all levels of performance enthusiasts’ count on the advanced technology built into NGK Spark Plugs. The V-Power Spark Plug by NGK uses a 90 Degree design nickel center electrode which produces the spark at the electrode’s edges. This then produces a hot, clean spark which makes better contact with better air/fuel mixture resulting in combustion that is complete and efficient. Features: Electrode materials - Many use precious metals such as platinum or gold/palladium for greater durability and lower voltage requirements. Electrode configurations - Fine-wire center electrodes provide better sparking and enhanced ignitability. Fine-wire ground electrodes further improve the ignitability of the plug. Insulator configurations - Special configurations are used for the insulator noses to improve throttle response. Stock Number: 2238 Center Electrode Core Material: Copper Core Center Electrode Tip Material: Nickel with V-Groove Gap Size: 0.040 in. Ground Configuration: Standard Ground Electrode Core Material: Nickel Core Ground Electrode Quantity: 1 Ground Electrode Tip Design: Standard Hex Size: 5/8” Manufacturer Heat Range: 5 Resistance: 5K ohms Seat Type: Tapered Thread Diameter: 0.551 in.