Iridium: 8 times stronger than platinum, 6 times harder, and with a melting point 1200 degrees higher. New laser welding techniques make it possible to make a spark plug with an iridium electrode. The result is a plug that requires less voltage to spark, burns more of the fuel in the cylinder, and can spark at LEANER air/fuel mixtures (see inset diagram), resulting in higher horsepower and better gas mileage.
NGK Iridium IX spark plugs provide unsurpassed performance in auto/light truck and powersports applications. The iridium alloy electrode is extremely durable to heat, corrosion and electrical wear. The fine wire electrode reduces the amount of energy required to create a spark while providing increased ignition efficiency and superior ignitability. The center electrode of Iridium IX spark plugs has an extra anti-fouling mechanism. A thermo edge between the center electrode and the insulator nose provides a gap for a secondary micro-discharge to jump and initiate a self-cleaning process.