NGK (6966) IMR9A-9H Spark Plug - Pack of 4 Provides the highest performance OEM upgrade available and extreme durability with 80,000 to 100,000 mile service life. Double precious metal construction uses a Fine-wire Iridium center electrode and Platinum ground electrodes for ultimate engine performance. Designed for the most advanced fuel-injected and turbocharged engines. Precision laser-welded electrode construction. Trivalent Metal Plating has superior anti-corrosion and anti-seizing properties.