Mercury – Quicksilver 5W-30 4-Stroke Full Synthetic Marine Engine Oil | Premium Marine Lubrication | Full Synthetic Protection | 8M0148475

Overview

If you’ve spent enough time on the water, you know how much trust you place in your engine every time you turn the key. It has to fire up cleanly, push through chop, idle smoothly through no-wake zones and take you home without hesitation. The oil inside it plays a bigger role than most people realize, quietly protecting everything that keeps you moving. The Mercury Marine part number 8M0148475, Quicksilver’s 5W-30 Full Synthetic 4-Stroke Marine Engine Oil (1 gallon), gives your engine that deep layer of protection — the kind that brings peace of mind whether you’re miles offshore or just looping around the lake with family.

Key Features

• Full synthetic 4-stroke marine engine oil for outboards, sterndrives and inboards
• SAE 5W-30 viscosity for consistent performance across temperature ranges
• Strong corrosion and wear protection to extend engine life
• Resists thermal breakdown during high heat and high-rpm operation
• Specialized marine additive package designed for heavy, wet marine conditions
• Meets or exceeds all FC-W marine engine warranty requirements
• One-gallon container for multiple fills or larger engines

Engine & Boat Compatibility

• Compatible with all Mercury and Quicksilver 4-stroke outboards
• Suitable for sterndrive and inboard engines requiring 5W-30 FC-W oil
• Works with major marine brands beyond Mercury when FC-W specifications are required
• Ideal for pontoons, center consoles, sport boats, cruisers, bass boats and towboats

Performance & Practical Benefits

Marine engines don’t have an easy life. They operate under heavier loads, at higher sustained speeds and in environments where moisture is always trying to work its way inside. That’s why this full synthetic formula stands out. It keeps its viscosity steady, even when the engine is pushed hard on long runs or in hot weather. That means a smoother, tighter protective film across bearings, camshafts and cylinder surfaces — the internal parts you never see but rely on with every mile.

On the water, you’ll feel the difference. Cold starts become cleaner. Acceleration feels steadier and more responsive. The engine holds its tone at cruising speed without that strained, overworked sound you get from oils that thin out. And when you’re idling for long stretches in no-wake zones, the oil continues to protect instead of breaking down or creating sludge.

Another major benefit is corrosion protection. Boats live in a world of humidity, spray and constant exposure to the elements. This oil’s additive package helps guard against internal rust, which can start quietly and cause real damage over time. With this oil, your engine simply feels more secure — ready for the long haul, the long weekend or the long season ahead.

Why Buy OEM

Not all oils are created equal, especially when it comes to marine engines. Automotive oils may look similar, but they’re not designed for the demands of watercraft. Quicksilver’s formula is engineered specifically for marine use, backed by decades of testing under real boating conditions. OEM oil ensures your engine stays within warranty guidelines, runs cooler, lasts longer and delivers the performance Mercury intended. If someone at the dock asked for honest advice, you’d probably say it straight: use the oil built for your engine, and you’ll avoid expensive problems down the road.

FAQ

Q1: Which engines is this oil designed for?

It works in all 4-stroke outboard, sterndrive and inboard marine engines requiring FC-W-rated 5W-30 oil.

Q2: What makes this better than automotive oil?

It’s formulated for marine stress — moisture, high loads, prolonged rpm — and offers superior corrosion protection.

Q3: How do I confirm this is the correct oil for my setup?

Check your manual. If it specifies FC-W or FC-W Catalyst Compatible 5W-30, this is the right match.

Q4: Can it be used in both saltwater and freshwater environments?

Absolutely — its corrosion-resistant additives protect in any environment.

Q5: Is the one-gallon size easy to use?

Yes. It’s convenient for larger engines or owners who prefer to keep enough oil on hand for multiple changes.