{"product_id":"ngk-spark-plugs-for-bmw-b58-m140i-m240i-340i-440i","title":"NGK Spark Plugs for BMW B58 — M140i, M240i, 340i, 440i","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003eThe recommended spark plug for all stock and tuned B58 applications. The NGK laser iridium plug specifically designed for the B58 platform, offering superior ignition performance and knock resistance over the factory-fitted items.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003eOn tuned cars running increased boost, the factory plugs are known to reach the end of their life sooner and can cause misfires under sustained load. Fresh NGKs with a tighter gap restore clean, consistent ignition across all cylinders.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003eWe recommend gapping to 0.024\" (0.6mm) for Stage 1 and above. Replace every 15,000–20,000 miles on a tuned car, or sooner if you notice any roughness or misfires.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal leading-[1.7]\"\u003e\u003cstrong\u003eFits:\u003c\/strong\u003e All Gen 1 B58-equipped BMWs including M140i (F20\/F21), M240i (F22\/F23), 340i (F30\/F31), 440i (F32\/F33\/F36), 540i (G30\/G31), 740i (G11\/G12).\u003c\/p\u003e","brand":"NGK","offers":[{"title":"Default Title","offer_id":51075050864946,"sku":"NGK94201x6","price":79.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1509\/8328\/files\/s-l1600_94315680-23d9-48b5-83f6-fd99a5571e68.webp?v=1771684366","url":"https:\/\/wayside-performance.co.uk\/products\/ngk-spark-plugs-for-bmw-b58-m140i-m240i-340i-440i","provider":"Wayside Performance ","version":"1.0","type":"link"}