{"product_id":"mercury-25w-40-4-stroke-marine-engine-oil-1-quart-fc-w-certified-catalyst-compatible","title":"MERCURY 25W-40 4‑Stroke Marine Engine Oil, 1 Quart — FC-W Certified, Catalyst Compatible","description":"\u003cp\u003e\u003cstrong\u003eMERCURY 25W-40 4-Stroke Marine Engine Oil (1 qt, part 8M0078627) is a marine-grade motor oil formulated to protect four-stroke outboards, sterndrives and inboards from wear, corrosion and viscosity breakdown on and off the water.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eBoating engines face salt, moisture and stop-start operation that automotive oils are not engineered to handle. This Mercury-labeled 25W-40 oil combines a robust base-stock blend with a targeted additive package to maintain lubricant film, resist thermal thinning, and help reduce corrosion in harsh marine environments. It meets or exceeds marine industry standards, including FC-W and FC-W Catalyst Compatible certifications, and is approved for use where 25W-40 is specified by the engine maker.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this oil protect engines used in saltwater and freshwater?\u003c\/h3\u003e\n\u003cp\u003eThis formula includes corrosion inhibitors and anti-wear agents tailored for marine exposure, helping preserve metal surfaces during operation and storage. The additives form a protective layer that combats rust and pitting caused by moisture and electrolytes in seawater.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSpecialized corrosion inhibitors for on- and off-water protection\u003c\/li\u003e\n  \u003cli\u003eWear-reducing additives to extend component life\u003c\/li\u003e\n  \u003cli\u003eStabilized formulation to resist oxidation and sludge\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhy choose 25W-40 for my four-stroke outboard or sterndrive?\u003c\/h3\u003e\n\u003cp\u003e25W-40 provides a balanced viscosity profile for many mid- to high-temperature marine operating conditions, maintaining a protective oil film at operating temperatures while offering acceptable cold-start performance where 25W cold rating is suitable. Use this grade where the engine manufacturer specifies 25W-40 to meet warranty and performance requirements.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMaintains viscosity under load and high heat\u003c\/li\u003e\n  \u003cli\u003eCompatible with Mercury, MerCruiser and other leading brands\u003c\/li\u003e\n  \u003cli\u003eRecommended when engine specs call for 25W-40\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eIs this oil compatible with catalytic systems and industry standards?\u003c\/h3\u003e\n\u003cp\u003eYes — the product is certified FC-W and marked FC-W Catalyst Compatible, indicating it complies with marine fuel and emissions-related performance benchmarks and is formulated to avoid harming catalyst systems. It also surpasses common marine warranty and manufacturer recommendations for four-stroke oils.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFC-W certified for marine four-stroke engines\u003c\/li\u003e\n  \u003cli\u003eCatalyst compatible to protect emission-control components\u003c\/li\u003e\n  \u003cli\u003eMeets or exceeds OEM warranty requirements\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does Mercury ensure consistent quality in this oil?\u003c\/h3\u003e\n\u003cp\u003eMercury produces this lubricant to its original equipment manufacturer specifications, using decades of marine-engine testing and manufacturing experience. Strict quality controls and blend standards help deliver repeatable viscosity, additive performance and protection across production batches.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFormulated and produced to Mercury OEM specifications\u003c\/li\u003e\n  \u003cli\u003eBacked by factory testing and marine engineering know-how\u003c\/li\u003e\n  \u003cli\u003eDesigned for consistency between fills and seasons\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: Boaters, professional marine technicians and owners of four-stroke outboard, sterndrive and inboard engines who need a reliable, warranty-compliant 25W-40 marine oil. It’s suited for recreational and light commercial vessels operating in both freshwater and saltwater where manufacturer guidance calls for this viscosity and FC-W certification.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I use this oil in both outboard and sterndrive engines?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. This 25W-40 oil is formulated for four-stroke outboard, sterndrive and inboard engines where 25W-40 is specified.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Is the Mercury 25W-40 compatible with catalytic exhaust systems?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. It is certified FC-W Catalyst Compatible to ensure compatibility with catalytic components.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"MERCURY","offers":[{"title":"Default Title","offer_id":67593265283257,"sku":"B00K87NK70","price":58.9,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0822\/3765\/3177\/files\/mercury-25w-40-front-label-quart.jpg?v=1790573816","url":"https:\/\/redleafauto.ca\/products\/mercury-25w-40-4-stroke-marine-engine-oil-1-quart-fc-w-certified-catalyst-compatible","provider":"Redleaf Auto","version":"1.0","type":"link"}