Quicksilver 10W-40 Marine Engine Oil 1 Gallon — 4-Stroke, FC-W Compliant, NMMA Rust Protection

Quicksilver 10W-40 4-Stroke Marine Engine Oil (1 gallon) is a mineral-based lubricant formulated to protect and maintain four-stroke outboards, sterndrives, and inboard marine engines under marine operating conditions.

Backed by the Quicksilver name — a supplier trusted across marine and powersports for over six decades — this 10W-40 FC-W compliant oil is made to meet or exceed marine manufacturers' warranty specifications. It preserves engine viscosity, resists varnish and sludge formation, and offers rust protection required for NMMA certification. The one-gallon bottle (part number 8M0148477) is ready for routine service intervals and on-board maintenance, helping keep marine engines operating smoothly in saltwater and freshwater environments.

What engines can I use this oil in?

This 10W-40 mineral oil is intended for all four-stroke marine outboard motors as well as inboard and sterndrive engines that specify an FC-W or compatible marine oil. Always consult your engine owner or service manual for the manufacturer’s recommended viscosity and service category before changing oil. Quicksilver formulates this product to meet broad marine requirements and warranty specifications.

• Suitable for four-stroke outboards, sterndrives, and inboards
• Meets FC-W and FC-W catalyst compatibility where required
• Designed to align with NMMA rust-protection standards
• Manufacturer part number: 8M0148477, one-gallon bottle

How does this oil protect engines during high-rpm or heavy-use boating?

Quicksilver 10W-40 is formulated to maintain protective viscosity under heat and stress, reducing metal-to-metal wear during sustained high-rpm operation. It also contains additives to limit varnish and sludge buildup, which helps preserve oil passages and valve train components over long intervals. Regular use supports reliable performance when engines are pushed hard on tow, trolling, or cruising runs.

• Stable viscosity for high-temperature, high-rpm conditions
• Additive package minimizes varnish and sludge formation
• Helps reduce piston and cam wear under load

Will this oil help prevent corrosion and meet warranty requirements?

Yes — the formulation exceeds the corrosion protection requirements needed for NMMA certification and is designed to meet or surpass marine manufacturers’ warranty criteria. Using an approved marine oil like this one supports warranty compliance when the engine maker specifies FC-W or similar categories. Still, keep records of oil changes and follow service schedules to remain within warranty terms.

• Exceeds rust protection needed for NMMA certification
• Formulated to satisfy marine OEM warranty recommendations
• Recommended to retain service records for warranty compliance

How should I use and store this one-gallon bottle?

The bottle is sized for easy fueling and on-board storage. Change oil according to your engine’s manual and local marine conditions—more frequent service may be needed for heavy use or contaminated water. Store the sealed container in a cool, dry place away from direct sunlight and extreme temperatures to preserve additive effectiveness.

• Follow engine manufacturer’s change intervals and instructions
• Use in clean funnels or oil-change kits to avoid contamination
• Store sealed away from heat and direct sun to protect additives

Who is this for? Boat owners, professional technicians, and fleet operators who run four-stroke marine outboards, sterndrives, or inboards and need a reliable, OEM-aligned mineral oil will find this Quicksilver 10W-40 ideal. It’s suited for recreational boaters and commercial users who require an oil that maintains viscosity under load, offers proven rust and wear protection, and helps meet manufacturer warranty specifications. If your engine manual calls for an FC-W or marine 10W-40 mineral oil, this one-gallon Quicksilver option is a practical choice for routine service and on-the-water peace of mind.