NGK Iridium IX spark plugs are specifically designed for the performance enthusiast. Iridium IX provides outstanding acceleration, high fuel efficiency and durability. NGK Iridium IX plugs offer extreme ignitability and exceptional anti-fouling. Tapered cut ground electrode provides improved starting, idling and throttle response. The Iridium fine wire center electrode's durability is six times harder than platinum. Iridium alloy's extremely high melting point is perfect for today's engines. For even greater performance consider upgrading to an NGK Ruthenium HX plug. NGK Iridium IX spark plugs are specifically designed for the performance enthusiast. Iridium IX provides outstanding acceleration, high fuel efficiency and durability. BMW 2010-06; HON 2011-10; LAND ROVER 2011-08; LEXUS 2014-07; M-BENZ 2011-03; SAAB 2009-06; SUBARU 2014-01; SUZ 2012-09; TOYOTA 2014-03; VOLVO 2011-04, O/B - 2006-01 MERCURY, 2005-00 YAM