Quicksilver 25W-40 4-Stroke Synthetic Blend Marine Engine Oil — 1 Gallon, FC-W Corrosion & Wear Protection

Quicksilver 25W-40 4-stroke synthetic blend marine engine oil (1 gallon) is a corrosion-resistant, wear-protecting lubricant engineered for high-rpm outboards and sterndrives.

Clean, stable oil is one of the simplest ways to extend the life of marine engines. This Quicksilver formula is a synthetic blend designed specifically for 4-stroke outboards and sterndrive applications, meeting or exceeding marine industry standards including FC-W and FC-W catalyst compatibility. It’s produced to Mercury Marine original equipment specifications, making it a direct replacement for part number 8M0078630 and suitable for a wide range of recreational and commercial boats.

How does this oil protect my 4-stroke outboard at high RPMs?

The 25W-40 viscosity and synthetic blend base deliver strong film strength under heavy loads and elevated temperatures. That reduces metal-to-metal contact and helps prevent accelerated wear during long runs or high-rev operation.

• High viscosity retention at operating temperature for consistent lubrication
• Enhanced wear additives to protect bearings and cam trains
• Formulation tested for high-rpm outboard environments

Will it prevent corrosion and compatibility issues in marine use?

This oil includes corrosion inhibitors formulated for wet, salty, and humid marine environments. It’s also FC-W rated and catalyst-compatible, meaning it meets marine industry chemistry standards and avoids interference with emissions-control components.

• Corrosion-resistant additive package for internal engine protection
• Meets FC-W and catalyst compatibility to fit marine OEM specs
• Produced to Mercury Marine OEM requirements for application confidence

Is this Quicksilver oil an exact replacement for my Mercury part?

Yes—this product is a direct replacement for Mercury Marine part 8M0078630 and carries manufacturer part number 8M0078623. Using an OEM-matching oil simplifies service and helps preserve warranty alignment when recommended by the manufacturer.

• Direct OEM replacement for Mercury 8M0078630
• Manufactured to Mercury Marine specifications
• Suitable for a broad range of 4-stroke outboards and sterndrives

How should I use and store this 1-gallon container effectively?

Use the oil following your engine manufacturer’s change-interval recommendations and dispose of used oil responsibly. Store the sealed one-gallon jug in a cool, dry place away from direct sunlight to maintain additive stability and shelf life.

• Follow engine manual for drain intervals and fill volumes
• Keep sealed until use; store upright in a cool, dry area
• Recycle used oil per local environmental regulations

Who is this for? Boaters and marine service professionals who want a dependable, OEM-grade lubricant for 4-stroke outboards and sterndrives will benefit most from this Quicksilver 25W-40 synthetic blend. It fits owners of Mercury-equipped vessels and other brands seeking proven corrosion resistance, high-rpm protection, and compatibility with marine emissions systems. Choose this one-gallon container if you need a practical size for routine maintenance or workshop stocking, and prefer a product designed and tested specifically for rugged marine conditions.