{"product_id":"sierra-premium-blend-heavy-duty-marine-engine-oil-15w40-qt","title":"Sierra Premium Blend Heavy Duty Marine Engine Oil 15W-40 – 1 Qt","description":"\u003ch2\u003eSierra Premium Blend Heavy Duty Marine Engine Oil 15W-40 – 1 Qt\u003c\/h2\u003e\n\u003cp\u003eEngineered for heavy-duty inboard marine engines, this 15W-40 premium blend oil is built for cruisers, towboats, and high-hour diesel or gasoline inboard applications that demand more than a standard marine oil can deliver. It meets API CK-4 (diesel) and API SM (gasoline) service classifications and is suitable for all fuel sulfur levels — making it a versatile choice for both diesel and gasoline inboard engines in demanding marine environments.\u003c\/p\u003e\n\u003cp\u003eThe 1-quart size is ideal for topping up between oil changes, keeping a spare aboard, or purchasing the exact quantity needed for a partial service.\u003c\/p\u003e\n\n\u003ch3\u003eKey Benefits\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eMeets API CK-4 diesel and API SM gasoline service classifications\u003c\/li\u003e\n\u003cli\u003eSuitable for all fuel sulfur levels — including high-sulfur diesel\u003c\/li\u003e\n\u003cli\u003ePremium blend formula delivers heavy-duty protection for high-load inboard applications\u003c\/li\u003e\n\u003cli\u003eCompatible with MerCruiser, Indmar, Pleasurecraft, Crusader, Volvo Penta, and Mastercraft engine specifications\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot for use in gasoline engines equipped with catalytic converters\u003c\/strong\u003e — see FC-W Catalyst Compatible oils for those applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eViscosity:\u003c\/strong\u003e 15W-40\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Premium Blend\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVolume:\u003c\/strong\u003e 1 Quart\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAPI Rating:\u003c\/strong\u003e CK-4 (diesel) \/ SM (gasoline)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Heavy-duty gasoline and diesel inboard marine engines\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCatalyst Compatible:\u003c\/strong\u003e No — not for use with catalytic converter-equipped engines\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eRelated Products\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/sierra-premium-blend-heavy-duty-marine-engine-oil-15w40-5qt\"\u003eSierra Heavy Duty 15W-40 Marine Engine Oil – 5 Qt\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/sierra-25w40-fcw-catalyst-compatible-4-stroke-marine-engine-oil-qt\"\u003eSierra 25W-40 FC-W Catalyst Compatible Marine Engine Oil – 1 Qt\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/sierra-25w40-fcw-catalyst-compatible-4-stroke-marine-engine-oil-5-qt\"\u003eSierra 25W-40 FC-W Catalyst Compatible Marine Engine Oil – 5 Qt\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\u003ch3\u003eParts Desk Insights\u003c\/h3\u003e\n\u003cp\u003eThe 1-quart size is best for topping up oil between scheduled changes or keeping a spare aboard — most inboard engines require 4–8 quarts for a full oil change, so the \u003ca href=\"\/products\/sierra-premium-blend-heavy-duty-marine-engine-oil-15w40-5qt\"\u003e5-quart jug\u003c\/a\u003e is the more practical choice for a complete service. The 15W-40 heavy duty spec is correct for older and high-displacement inboard diesel and gasoline engines — trawlers, cruisers, and towboats running Indmar, Crusader, Pleasurecraft, or older MerCruiser and Volvo Penta inboard engines that specify 15W-40. It is \u003cstrong\u003enot\u003c\/strong\u003e suitable for engines with catalytic converters; for those, use the \u003ca href=\"\/products\/sierra-25w40-fcw-catalyst-compatible-4-stroke-marine-engine-oil-qt\"\u003eSierra 25W-40 FC-W Catalyst Compatible oil\u003c\/a\u003e instead. Always confirm your engine’s oil specification in the owner’s manual before purchasing.\u003c\/p\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51199659212836,"sku":"47-95542","price":15.89,"currency_code":"CAD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/47-95542.jpg?v=1785611236","url":"https:\/\/marisolmarine.com\/products\/sierra-premium-blend-heavy-duty-marine-engine-oil-15w40-qt","provider":"Marisol Marine Company","version":"1.0","type":"link"}