{"product_id":"denso-sk20hr11-iridium-platinum-spark-plugs-4-pack-3421-genuine-denso","title":"Denso SK20HR11 Iridium Platinum Spark Plugs – 4-Pack 3421 (Genuine Denso)","description":"\u003ch2\u003eOverview\u003c\/h2\u003e\u003cp\u003eDiscover the DENSO SK20HR11 Iridium Platinum spark plugs, a genuine four-pack designed to support reliable ignition in everyday driving. The SK20HR11 uses a durable iridium-platinum alloy to resist wear, helping maintain a strong, consistent spark across miles. Cataloged as 3421, these plugs align with a wide range of compatible engines, offering trusted performance from a brand you can rely on.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat you get\u003c\/strong\u003e: A convenient four-piece set that simplifies maintenance planning. This item ships free within the United States and territories, making it easy to stock up for future service without extra shipping costs.\u003c\/p\u003e\u003ch3\u003eWhy drivers consider this set\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eGenuine DENSO 3421 spark plugs with brand backing\u003c\/li\u003e\n\u003cli\u003eIridium-platinum electrode design for high durability and consistent sparking\u003c\/li\u003e\n\u003cli\u003e4-piece pack supports full replacement in one service\u003c\/li\u003e\n\u003cli\u003eFree shipping to USA and territories with this item\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReal-life use cases\u003c\/h3\u003e\u003cp\u003eWhether you are prepping for a seasonal tune-up, replacing worn plugs in an older vehicle, or updating a fleet maintenance schedule, this 4-pack makes it easier to refresh ignition performance without placing multiple orders.\u003c\/p\u003e\u003cp\u003ePerformance notes: results can vary by vehicle, but many users report smoother starts, quicker warm-up, and more stable idle when plugs are in good condition. The iridium-platinum tips are designed to resist wear over time, potentially reducing misfires and improving reliability in some cases.\u003c\/p\u003e\u003ch3\u003eInstallation tips\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eConsult your vehicle manual for torque specs and follow recommended procedures\u003c\/li\u003e\n\u003cli\u003eHandle plugs carefully to avoid damaging electrode tips\u003c\/li\u003e\n\u003cli\u003eUse manufacturer guidance for thread lubrication or anti-seize where advised\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eIn short, the DENSO 3421 four-pack offers a trusted brand, a robust material build, and the convenience of bulk packaging for easier maintenance planning.\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: What’s included in this DENSO 3421 four-pack?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: A genuine four-pack of SK20HR11 spark plugs, model 3421, ready for installation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does this item qualify for free shipping?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes, free shipping is offered to the USA and territories for this item.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Denso","offers":[{"title":"Default Title","offer_id":42470966362197,"sku":"B00PD6EWPU","price":55.23,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0632\/3270\/4597\/files\/denso-sk20hr11-iridium-platinum-spark-plugs-3421-4pcs.jpg?v=1778158079","url":"https:\/\/plentytorque.co.uk\/products\/denso-sk20hr11-iridium-platinum-spark-plugs-4-pack-3421-genuine-denso","provider":"PlentyTorque","version":"1.0","type":"link"}