{"product_id":"denso-iridium-platinum-spark-plugs-sk20hr11-3421-6-pack-oem-fit-long-life-ignition","title":"Denso Iridium-Platinum Spark Plugs SK20HR11 (3421) 6-Pack — OEM Fit, Long-Life Ignition","description":"\u003cp\u003e\u003cstrong\u003eDENSO SK20HR11 (3421) is a genuine six-piece power pack of iridium-platinum spark plugs engineered for consistent ignition, extended electrode life, and factory-quality fitment.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThese DENSO 3421 spark plugs combine an iridium center electrode with a platinum ground electrode in a factory-packed six-piece set designed to meet or exceed original equipment specifications. The SK20HR11 construction emphasizes precise spark delivery and durability under a wide range of driving conditions. Supplied as a power pack of six, they’re ideal for multi-cylinder tune-ups and routine maintenance where OEM-equivalent performance is required.\u003c\/p\u003e\n\n\u003ch3\u003eWhat makes the SK20HR11 iridium-platinum design different?\u003c\/h3\u003e\n\u003cp\u003eThe SK20HR11 uses a fine iridium center electrode paired with a platinum ground electrode to reduce wear and support stable sparking across the service life. Iridium’s hardness allows a much finer electrode tip, which lowers required voltage and focuses the spark for efficient combustion initiation.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFine iridium center electrode for concentrated spark and lower firing voltage\u003c\/li\u003e\n  \u003cli\u003ePlatinum ground electrode for improved wear resistance and longevity\u003c\/li\u003e\n  \u003cli\u003eRobust ceramic insulator and metal shell for thermal stability\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow will these plugs affect everyday driving and starting?\u003c\/h3\u003e\n\u003cp\u003eIn normal driving, the precise spark characteristics help maintain consistent ignition timing and smoother idle. That can translate into dependable cold starts and fewer misfires as the plugs age, while keeping engine response predictable across typical operating conditions.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eReliable starts from improved spark focus\u003c\/li\u003e\n  \u003cli\u003eStable idle and reduced misfires during routine use\u003c\/li\u003e\n  \u003cli\u003eSuitable for both city stop-and-go and highway driving\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eAre these DENSO plugs compatible with my vehicle and how easy is installation?\u003c\/h3\u003e\n\u003cp\u003eSK20HR11 (DENSO 3421) fits applications that specify the SK20HR11 or equivalent part numbers—always cross-reference your vehicle’s service manual or parts catalog. Installation follows standard spark plug replacement procedures and is straightforward for anyone with basic tools and mechanical experience.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCheck compatibility against your vehicle’s specified spark plug part numbers\u003c\/li\u003e\n  \u003cli\u003eInstall with proper torque and a clean plug hole to ensure correct sealing\u003c\/li\u003e\n  \u003cli\u003eSold as a six-piece power pack for complete multi-cylinder replacements\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow long can I expect these spark plugs to last compared to conventional plugs?\u003c\/h3\u003e\n\u003cp\u003eIridium and platinum alloys are selected for wear resistance, so SK20HR11 plugs typically outlast standard copper plugs under comparable conditions. Lifespan varies by engine design, driving style, and maintenance, but the materials and DENSO’s manufacturing standards prioritize extended service intervals.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIridium and platinum resist electrode erosion better than copper\u003c\/li\u003e\n  \u003cli\u003eDurability supports longer intervals between replacements when used per manufacturer guidance\u003c\/li\u003e\n  \u003cli\u003ePerformance retention depends on engine health and operating environment\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The DENSO SK20HR11 (3421) six-pack is aimed at vehicle owners, mechanics, and fleets seeking OEM-quality replacement spark plugs with enhanced electrode materials. It’s a practical choice for those performing full multi-cylinder tune-ups, anyone wanting longer service life than standard copper plugs, and people who prioritize reliable ignition performance that matches factory specifications.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: How many spark plugs are included in this DENSO power pack?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: This listing contains one power pack with six DENSO SK20HR11 (3421) spark plugs.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can SK20HR11 plugs be used as a direct replacement for OEM parts?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes, SK20HR11 (DENSO 3421) is manufactured to meet OEM fit and performance for compatible applications; confirm fitment with your vehicle guide.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Denso","offers":[{"title":"Default Title","offer_id":48080857104542,"sku":"B00PD66Q86","price":102.5,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/denso-sk20hr11-front-packaging.jpg?v=1785790678","url":"https:\/\/northtrailauto.ca\/products\/denso-iridium-platinum-spark-plugs-sk20hr11-3421-6-pack-oem-fit-long-life-ignition","provider":"North Trail Auto","version":"1.0","type":"link"}