Autolite has over 100 years of engineering experience and has sold over 11 billion plugs. Designed and engineered in the USA, Autolite Double Platinum spark plugs feature platinum-to-platinum firing which virtually eliminates gap erosion, reduces misfires and increases durability of the plug. Warrantied for 5 years. Consider upgrading to Autolite Iridium XP spark plugs for increased performance. Autolite is an Official NASCAR Performance Partner.