{"product_id":"ngk-itr4a15-laser-iridium-spark-plug-replaces-mercury-33-8m2018369","title":"NGK ITR4A15 Laser Iridium Spark Plug - Replaces Mercury 33-8M2018369","description":"\u003cp\u003eThe NGK ITR4A15 is a Laser Iridium spark plug built as an actual OE or equivalent replacement plug, offering a combination of performance and longevity for engines that call for this exact plug. The center electrode is tipped in iridium, a material with durability six times harder than platinum, so the tip resists wear over long service intervals while maintaining a consistent spark. Behind that tip sits a 98% pure copper core paired with high-grade pure alumina ceramic insulation, a combination designed to prevent the plug from overheating while still delivering reliable starts. The plug uses a standard ground electrode configuration, with a nickel ground electrode core and a copper center electrode core, and carries a 5000 ohm resistance rating to help suppress ignition interference. Each NGK ITR4A15 is tested to NGK's quality and durability standards before it ships. It is a direct cross-reference for Mercury part numbers 33-8M2018369, 33-884019001, and 338M0204739, so it is commonly ordered as a replacement plug where those numbers are specified. As with any spark plug, always check your engine and maintenance manual for the correct plug and use only what your engine's original equipment manufacturer recommends, since using the wrong plug can reduce performance, reduce fuel economy, or cause engine damage.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e NGK\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e ITR4A15\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Spark Plug\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eResistance:\u003c\/strong\u003e 5000 ohms\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGround Configuration:\u003c\/strong\u003e Standard\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGround Electrode Core Material:\u003c\/strong\u003e Nickel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCenter Electrode Core Material:\u003c\/strong\u003e Copper\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCenter Electrode Tip Material:\u003c\/strong\u003e Iridium\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Size:\u003c\/strong\u003e 14mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit Count:\u003c\/strong\u003e 1 spark plug\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 087295155998, 489394319895\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.15 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eCheck your engine and maintenance manual for the correct spark plug and only use as recommended by your engine's original equipment manufacturer. Using the wrong plug can reduce optimum performance, reduce fuel economy, or cause damage to your engine.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMercury 33-8M2018369\u003c\/li\u003e\n\u003cli\u003eMercury 33-884019001\u003c\/li\u003e\n\u003cli\u003eMercury 338M0204739\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part numbers does the NGK ITR4A15 replace?\u003c\/strong\u003e The NGK ITR4A15 replaces Mercury part numbers 33-8M2018369, 33-884019001, and 338M0204739, so it can be ordered as a direct cross-reference for any of those numbers.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the ITR4A15 a genuine NGK plug or an aftermarket copy?\u003c\/strong\u003e It is a genuine NGK Laser Iridium spark plug, described as an actual OE or equivalent replacement plug rather than a generic aftermarket copy.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the center electrode tip made of?\u003c\/strong\u003e Iridium tips the center electrode on the ITR4A15, a material with durability six times harder than platinum, which helps the plug hold up over long service intervals.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat resistance rating does this spark plug have?\u003c\/strong\u003e 5000 ohms is the resistance rating of the NGK ITR4A15, which helps suppress ignition interference.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the ITR4A15 weigh?\u003c\/strong\u003e The NGK ITR4A15 spark plug weighs 0.15 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat thread size does the ITR4A15 use?\u003c\/strong\u003e The ITR4A15 uses a 14mm thread size.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many spark plugs are included?\u003c\/strong\u003e Each unit of the NGK ITR4A15 includes 1 spark plug.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat ground electrode configuration does this plug have?\u003c\/strong\u003e A standard ground electrode configuration is used on the ITR4A15, with a nickel ground electrode core and a copper center electrode core.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow does the ITR4A15's iridium tip compare to a standard plug?\u003c\/strong\u003e Six times harder than platinum is how NGK rates the iridium tip on the ITR4A15, which is designed to outlast conventional ground electrode materials while providing reliable starts.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I install the ITR4A15 in any engine that takes a spark plug?\u003c\/strong\u003e No - only install the NGK ITR4A15 if it is the plug specified in your engine's owner's manual, since using the wrong plug can reduce optimum performance, reduce fuel economy, or cause engine damage.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat UPC codes are associated with this spark plug?\u003c\/strong\u003e The NGK ITR4A15 is listed under UPC codes 087295155998 and 489394319895.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat core material is used for the center electrode?\u003c\/strong\u003e A copper core sits beneath the iridium tip in the ITR4A15's center electrode, which NGK uses for reliable heat dissipation and conductivity.\u003c\/p\u003e","brand":"NGK Spark Plugs","offers":[{"title":"Default Title","offer_id":49028254564571,"sku":"NGK-ITR4A15","price":11.42,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/ITR4A15__61905.1737885810.500.750.jpg?v=1785165236","url":"https:\/\/www.goodvibesmarina.com\/products\/ngk-itr4a15-laser-iridium-spark-plug-replaces-mercury-33-8m2018369","provider":"Good Vibes Marina","version":"1.0","type":"link"}