Denso Spark Plug Set to suit Subaru Forester and Subaru Outback 2.5L Petrol AWD models built from 2015 to 2025, supplied ready to fit with no modification required. Replacing plugs as a full set keeps cylinder-to-cylinder combustion even and prevents misfire codes. The Iridium centre electrode is 5.0mm in diameter, which lowers the voltage needed to jump the gap and improves cold starting. A trivalent metal plating on the shell resists corrosion and seizing in aluminium heads. Ribbed insulator construction prevents flashover to the coil boot. Service life of up to 60,000km is typical in normal conditions. Factory gap is set at 0.9mm and heat range 5 matches the original equipment specification. New stock, 24 Months warranty, and dispatched from our Australian warehouse.