{"product_id":"sierra-25w50-fcw-synthetic-blend-4-cycle-marine-engine-oil-4l","title":"Sierra 25W-50 FC-W Synthetic Blend 4-Cycle Marine Engine Oil – 4 L","description":"\u003ch2\u003eSierra 25W-50 FC-W Synthetic Blend Marine Engine Oil – 4 L\u003c\/h2\u003e\u003cp\u003eEngineered for the demands of the marine environment, this 25W-50 synthetic blend engine oil meets both \u003cstrong\u003eNMMA FC-W\u003c\/strong\u003e and \u003cstrong\u003eAPI SL\u003c\/strong\u003e certifications — the two benchmarks that matter most for 4-cycle outboard and inboard engines operating without a catalytic converter. The synthetic blend base provides a stable viscosity film across a wide temperature range, so your engine is protected whether you're idling in a hot marina or running hard offshore.\u003c\/p\u003e\u003cp\u003eThe formulation includes elevated levels of rust and corrosion inhibitors specifically chosen for salt and freshwater exposure, along with high-load additives that protect bearings and cylinder walls under sustained wide-open-throttle use.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eViscosity:\u003c\/strong\u003e 25W-50\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCertification:\u003c\/strong\u003e NMMA FC-W \/ API SL\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine type:\u003c\/strong\u003e 4-cycle outboard and inboard (non-catalytic converter)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVolume:\u003c\/strong\u003e 4 L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBase:\u003c\/strong\u003e Synthetic blend\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eParts Desk Insights\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eBest use case:\u003c\/strong\u003e Ideal for high-output 4-stroke outboard engines — particularly larger displacement motors (150 hp and up) running in saltwater or mixed conditions where corrosion protection and shear stability are priorities. Also well-suited for inboard gasoline engines in runabouts and cruisers that see regular seasonal use. If you run a smaller 4-stroke outboard or prefer a straight-weight option, see the \u003ca href=\"\/products\/sierra-95528-synthetic-blend-25w-50-fc-w-marine-engine-oil-1-l\"\u003eSierra 25W-50 FC-W Marine Engine Oil – 1 L\u003c\/a\u003e for single-quart top-ups or mixed-fleet stocking.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCompatibility note:\u003c\/strong\u003e Confirm your engine OEM spec calls for FC-W rated oil. Not intended for 2-stroke engines or engines equipped with catalytic converters.\u003c\/p\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51199652757540,"sku":"47-95523","price":101.89,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/47-95512_597b1e88-b5b9-45ea-be7d-2a2813b66ccf.jpg?v=1785611200","url":"https:\/\/marisolmarine.com\/products\/sierra-25w50-fcw-synthetic-blend-4-cycle-marine-engine-oil-4l","provider":"Marisol Marine Company","version":"1.0","type":"link"}