Quicksilver 25W-40 4-Stroke Marine Engine Oil — 1 Quart, FC-W Rated Corrosion Protection

Quicksilver 25W-40 4-Stroke Marine Engine Oil (1 qt) is a purpose-built engine lubricant formulated to protect sterndrive and outboard 4-stroke marine engines from wear and corrosion while supporting high-rpm performance.

Clean, correctly formulated oil is a key defense between moving engine parts and saltwater, heat and high load stress. Quicksilver’s marine-specific 25W-40 blend has been designed and tested for marine conditions, meeting and exceeding industry 4-stroke standards including FC-W and catalyst compatibility. Packaged in a convenient 32 oz (1 quart) bottle and identified by part number 8M0078619, it’s made to serve Mercury Marine equipment as well as other compatible marine and powersports engines.

How does this oil reduce corrosion and wear in marine engines?

The formulation uses additives and detergents selected for marine environments where salt, moisture and varying loads accelerate metal breakdown. Those additives form protective films, neutralize acids and keep internal surfaces cleaner so metal components slide with less friction.

• Anti-corrosion agents that inhibit rust formation on metal surfaces
• Wear-reducing additives that protect bearings and cams under load
• Detergents and dispersants that keep contaminants suspended for easier oil filtration

Will 25W-40 viscosity work for my high-rpm outboard or sterndrive?

25W-40 is chosen to balance cold-start flow and high-temperature film strength, particularly in higher-revving four-stroke outboards and sterndrives. The special viscosity modifiers help the oil maintain stable thickness at operating temperature, preserving lubrication during prolonged high-rpm runs.

• 25W rating supports acceptable cold-start performance in marine climates
• 40 high-temp rating provides robust oil film at operating temperatures
• Viscosity modifiers minimize thinning at sustained high RPM

Is this oil compatible with emissions components and manufacturer specs?

Quicksilver 25W-40 is formulated to meet common marine 4-stroke specifications, including FC-W, and is compatible with catalyst-equipped engines. That makes it suitable for engines requiring FC-W performance and for use in many Mercury Marine original equipment applications.

• Meets or exceeds marine FC-W performance requirements
• Catalyst-compatible formulation safe for emissions control parts
• Approved for use in many Mercury Marine and compatible OEM engines

How much oil comes in the bottle and how do I identify it?

This product is sold in a single 32 oz (1 quart) bottle for easy handling during routine service. It is labeled with Quicksilver branding and the manufacturer part number 8M0078619 to match OEM parts lists and service guides.

• 32 oz (1 quart) bottle sized for single-engine changes or top-offs
• Clear Quicksilver labeling for quick identification at the dock or workshop
• OEM part number 8M0078619 printed on the container for reference

Who is this for: Boaters, professional marine mechanics and powersports owners who need a reliable, marine-rated 4-stroke engine oil that balances protection and performance. It’s suitable for operators of sterndrives and outboards seeking an oil designed for saltwater use, high-rpm operation and compatibility with OEM requirements.

Features:

• Designed for use in 4-stroke marine engines
• Formulated to provide superior corrosion resistance and wear protection to maintain peak engine performance and reliability
• Special viscosity modifiers help to optimize the performance of high-rpm 4-stroke outboard motors
• 25W-40 viscosity
• 32 oz. bottle
• Manufacturer part number 8M0078619