Quicksilver 4-Stroke 10W-30 – Marine Outboard Engine Oil

Quicksilver 10W-30 4-Stroke Marine Engine Oil is developed by the same team behind Mercury and Mariner outboards, meaning it’s precisely tailored to the needs of marine engines – from small portable motors to mid-range outboards. The oil features a pure mineral base enhanced with an additive package that meets the marine FC-W (Four-Stroke Cycle, Water-Cooled) standard. This standard ensures the product passes specific tests for saltwater corrosion resistance, foaming, viscosity retention in presence of water/fuel, and overall engine protection in marine use.

Unlike automotive oils, Quicksilver 10W-30 is formulated to handle the challenges of boat engines: running at cooler operating temperatures, often higher sustained RPM, and exposure to moisture. The result is an oil that reliably shields bearings, pistons, and valvetrain components while also guarding against rust on internal parts during lay-up. The 10W-30 viscosity makes it a versatile choice for spring/fall conditions and mild to moderate climates – it’s fluid enough for good lubrication on cool mornings and robust enough for hot afternoons on the water.

Applications & Recommendations:

• Small to mid-size outboards: Mercury recommends 10W-30 for its FourStroke models typically up to ~75 HP, especially in climates with ambient temperatures below about 20-25°C (68-77°F). This oil is ideal for portable engines (4-6-10 HP) as well as mid-range units (15-60 HP) in moderate conditions. It allows easier pull-starting and quicker lubrication of components on cold start compared to heavier oils. (For larger Mercury engines or very hot tropical climates, Mercury often suggests 25W-40 oil; always check your engine’s manual.)
• Compatible with other brands: Quicksilver 10W-30 can also be used in Yamaha, Honda, Suzuki, and Johnson/Evinrude 4-stroke outboards, etc., that specify 10W-30 and carry FC-W or API SJ/SL classifications. It’s a universal marine oil – just ensure the viscosity and spec match your engine manufacturer’s recommendation.
• Packaging: Available in a ~1 L bottle (1 quart, ~946 ml) and a ~3.78 L jug (1 gallon). The 1L bottle is convenient for oil changes on a single small engine or occasional top-offs – for example, a 20-60 HP outboard often takes between 1 and 2.5 liters, so one or two bottles will cover it. The larger 3.78L jug is cost-effective for owners of bigger engines or multiple boats – it contains enough oil for a change on one 40-60 HP engine (with some left for topping up) or for complete service cycles on several small motors.
• Maintenance: Follow the recommended oil change interval (typically 100 hours or annually). For Mercury/MerCruiser four-stroke engines, always replace the oil filter when changing the oil. After refilling, use the dipstick to ensure the level is correct (between the marks). Avoid overfilling, as that can affect performance. Dispose of used oil in accordance with environmental regulations.
• Tip: If your boat operates in extremely humid conditions or makes frequent short trips (where the engine might not always reach full operating temperature), consider changing the oil a bit more frequently. This oil is formulated to handle some condensation or minor water intrusion, but fresh oil is always the best protection for your motor.