Mercury – Quicksilver 5W-30 4-Stroke Full Synthetic Marine Engine Oil | Premium Marine Lubrication | Full Synthetic Protection | 8M0148474

Overview

Anyone who spends time on the water knows how much trust we put into our engines. Long runs across open bays, slow crawls through winding channels, quick throttle bursts to beat the tide — your motor sees it all. And the oil inside it quietly carries the weight of every one of those moments. That’s why the Mercury Marine part number 8M0148474, Quicksilver’s 5W-30 Full Synthetic 4-Stroke Marine Engine Oil, feels like more than just an oil change. It’s peace of mind poured straight into your crankcase, giving your engine the protection it needs to keep delivering smooth, reliable days on the water.

Key Features

• Full synthetic 4-stroke marine engine oil designed for outboards, sterndrives and inboards
• SAE 5W-30 viscosity for dependable performance in a wide range of temperatures
• Strong resistance to thermal breakdown under high heat and high-rpm conditions
• Specialized additive package engineered specifically for marine engines
• Helps prevent varnish buildup, sludge formation and corrosion
• Meets or exceeds all FC-W marine engine oil requirements
• One-quart container for easy storage and clean handling

Engine & Boat Compatibility

• Suitable for all 4-stroke Mercury and Quicksilver outboards
• Compatible with sterndrive and inboard engines of all horsepower ranges
• Ideal for pontoons, bay boats, bass boats, cruisers, towboats and offshore vessels
• Works with most major marine engine brands that require FC-W-rated oil

Performance & Practical Benefits

Marine engines live a tough life. They run at higher sustained speeds, face constant moisture and deal with the stress of pushing heavy hulls through shifting conditions. That’s exactly where this oil shines. Its full synthetic formula maintains a steady viscosity even when the engine is working hard, which means your bearings, cam surfaces and cylinder walls stay protected with a smooth, consistent film.

Out on the water, you’ll feel the difference. Starts sound cleaner. Mid-range throttle feels tighter and more responsive. And long idle zones become less stressful, because you know the oil isn’t thinning or breaking down behind the scenes. The corrosion protection is another quiet advantage — it helps guard against the moisture that creeps into every marine engine, whether you run in saltwater or freshwater. With this oil in the crankcase, everything inside your engine just feels more secure, more prepared and more protected for the miles ahead.

Why Buy OEM

Marine engines aren’t car engines, and automotive oil simply can’t keep up with the loads and moisture exposure these motors face. Quicksilver’s formula is built specifically for the marine environment, backed by decades of Mercury engineering and testing. It meets every warranty requirement and is trusted by boaters who want their engines to last, not just run. Aftermarket formulas may look similar on paper, but they rarely hold up to the same standards of heat resistance, rust protection and load stability. If a friend asked for honest advice at the dock, you’d tell them the truth: run the oil your engine was designed for, and it will reward you with a longer, smoother life.

FAQ

Q1: Which engines is this oil designed for?

It works in all 4-stroke outboard, sterndrive and inboard marine engines that call for FC-W-rated oil.

Q2: What makes this different from automotive synthetic oil?

It’s engineered for the heat, moisture and load demands of marine use — something automotive oils aren’t built to handle.

Q3: How can I confirm this is the right oil for my engine?

Check your owner’s manual. If it calls for FC-W or FC-W Catalyst Compatible oil in 5W-30, this is the correct choice.

Q4: Can it be used in saltwater and freshwater boats?

Absolutely — its corrosion-resistant additive package is built for both environments.

Q5: Is it easy to use for DIY oil changes?

Yes, the one-quart bottle is simple to handle, and the formula flows cleanly for quick, neat oil changes.