Denso (5731) IXU01-27 Iridium Racing Spark Plug, (Pack of 1)
No-compromise, top of the line race spark plug for the most serious enthusiast. 0.4mm Iridium-Rhodium alloy center electrode requires less voltage to fire and increases firing performance. 100% pure Platinum 0.8mm ground electrode reduces risk of melting the plug during harsh racing conditions.