{"product_id":"mercury-4-stroke-full-synthetic-marine-engine-oil-25w-40-1l-8m0078641","title":"Mercury 4-Stroke Full Synthetic Marine Engine Oil – 25W-40, 1L | 8M0078641","description":"\u003ch2\u003eMercury 4-Stroke Full Synthetic Marine Engine Oil – SAE 25W-40, 1L\u003c\/h2\u003e\n\n\u003cp\u003eProtect your Mercury 4-stroke engine with this genuine OEM full synthetic marine engine oil. The full synthetic formula delivers superior thermal stability, oxidation resistance, and wear protection compared to conventional and synthetic-blend oils — making it the right choice for high-output engines, extended service intervals, or demanding operating conditions. Includes marine-specific corrosion inhibitors and shear-stability additives engineered for both saltwater and freshwater environments.\u003c\/p\u003e\n\n\u003ch3\u003ePart Details\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e 8M0078641\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMercury Reference:\u003c\/strong\u003e 92-8M0078641\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Mercury Marine\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e 4-Stroke Marine Engine Oil – Full Synthetic\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eViscosity:\u003c\/strong\u003e SAE 25W-40\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContainer Size:\u003c\/strong\u003e 1 Litre\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCertification:\u003c\/strong\u003e NMMA FC-W and FC-W Catalyst Compatible\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCondition:\u003c\/strong\u003e New OEM\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eCompatible Applications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eMercury FourStroke outboards – 2.5 HP through 400 HP\u003c\/li\u003e\n\u003cli\u003eMercury Pro XS FourStroke outboards\u003c\/li\u003e\n\u003cli\u003eMercury Verado FourStroke outboards\u003c\/li\u003e\n\u003cli\u003eMerCruiser 3.0L, 4.3L V6, 5.0L V8, 5.7L V8, 6.2L V8, 7.4L V8, 8.2L V8 sterndrives and inboards\u003c\/li\u003e\n\u003cli\u003eAny 4-stroke marine engine where SAE 25W-40 full synthetic is specified — always confirm in your owner's manual\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull synthetic formula\u003c\/strong\u003e – superior thermal stability and oxidation resistance vs. conventional or synthetic-blend oils\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFC-W and FC-W Catalyst Compatible certified\u003c\/strong\u003e – safe for catalyst-equipped engines\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdvanced marine corrosion protection\u003c\/strong\u003e – enhanced inhibitors for saltwater and humid environments\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShear stability\u003c\/strong\u003e – maintains viscosity under sustained high-RPM and heavy-load operation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExtended drain capability\u003c\/strong\u003e – full synthetic base resists thermal breakdown longer than conventional oils\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eService Interval\u003c\/h3\u003e\n\u003cp\u003eChange engine oil and filter at the interval specified in your engine owner's manual — typically every 100 hours or annually, whichever comes first. Full synthetic oil may support extended drain intervals on some engines; always follow Mercury's published guidance for your specific model and serial number range.\u003c\/p\u003e\n\n\u003ch3\u003eTechnical FAQ\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhat's the difference between 8M0078641 and \u003ca href=\"\/products\/mercury-4-stroke-marine-engine-oil-25w-40-1l-part-8m0078639\"\u003e8M0078639\u003c\/a\u003e?\u003c\/strong\u003e Both are SAE 25W-40 Mercury marine oils. 8M0078639 is a synthetic blend; 8M0078641 is full synthetic. Full synthetic offers better thermal stability and oxidation resistance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhat's the difference between 8M0078641 and \u003ca href=\"\/products\/mercury-4-stroke-synthetic-blend-engine-oil-25w-40-4l-8m0078642\"\u003e8M0078642\u003c\/a\u003e?\u003c\/strong\u003e Same full synthetic oil — 8M0078641 is the 1L bottle; 8M0078642 is the 4L jug.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCan I use automotive synthetic oil instead?\u003c\/strong\u003e No. Automotive oils lack the marine-specific corrosion inhibitors required for boat engines and can void your warranty.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIs this FC-W Catalyst Compatible?\u003c\/strong\u003e Yes — safe for engines equipped with catalytic converters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhat if my engine specifies 10W-30?\u003c\/strong\u003e Use the viscosity in your owner's manual. See the \u003ca href=\"\/products\/mercury-4-stroke-engine-oil-10w-30-1l-part-8m0078637\"\u003eMercury 10W-30 Engine Oil – 1L (8M0078637)\u003c\/a\u003e for that grade.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eAlso Available\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/mercury-4-stroke-synthetic-blend-engine-oil-25w-40-4l-8m0078642\"\u003eMercury 4-Stroke Full Synthetic Oil – 4L (8M0078642)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/mercury-4-stroke-marine-engine-oil-25w-40-1l-part-8m0078639\"\u003eMercury 4-Stroke Synthetic Blend Oil – 1L (8M0078639)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/mercury-4-stroke-marine-engine-oil-25w-40-4l-part-8m0078640\"\u003eMercury 4-Stroke Synthetic Blend Oil – 4L (8M0078640)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/mercury-4-stroke-high-performance-engine-oil-25w-50-1-qt-8m0078013\"\u003eMercury 25W-50 High Performance Oil – 1 Qt (8M0078013)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/mercury-4-stroke-engine-oil-10w-30-1l-part-8m0078637\"\u003eMercury 10W-30 Engine Oil – 1L (8M0078637)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/mercury-4-stroke-engine-oil-10w-30-4l-part-8m0078638\"\u003eMercury 10W-30 Engine Oil – 4L (8M0078638)\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch3\u003eParts Desk Insights\u003c\/h3\u003e\n\u003cp\u003eThe full synthetic 8M0078641 is the right call when an engine sees hard use, extended service intervals, or operates across a wide temperature range — the full synthetic base resists thermal breakdown and oxidation significantly better than the \u003ca href=\"\/products\/mercury-4-stroke-marine-engine-oil-25w-40-1l-part-8m0078639\"\u003esynthetic-blend 8M0078639\u003c\/a\u003e. The most common customer question is whether any 25W-40 marine oil is interchangeable: the viscosity matches, but full synthetic and synthetic-blend oils have different additive packages and drain-interval characteristics — if the service manual specifies full synthetic, use full synthetic. The 1L bottle is best suited for top-ups or smaller single-cylinder engines; for a full oil change on most Mercury 4-stroke outboards or MerCruiser sterndrives, the \u003ca href=\"\/products\/mercury-4-stroke-synthetic-blend-engine-oil-25w-40-4l-8m0078642\"\u003e4L jug (8M0078642)\u003c\/a\u003e is the more practical purchase.\u003c\/p\u003e","brand":"MERC","offers":[{"title":"Default Title","offer_id":43563912953892,"sku":"8M0078641","price":27.6,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/8M0078641.png?v=1771534543","url":"https:\/\/marisolmarine.com\/products\/mercury-4-stroke-full-synthetic-marine-engine-oil-25w-40-1l-8m0078641","provider":"Marisol Marine Company","version":"1.0","type":"link"}