Superior Protection Against Engine Wear
Marine engines operate under high loads and RPMs for extended periods of time, causing traditional automotive oils to break down and lose viscosity. To ensure good protection, the NMMA set minimum shear stability requirements for FC-W. AMSOIL Formula 4-Stroke® Marine Synthetic Engine Oil greatly exceeds the FC-W shear stability requirements, outperforming competitive oils to deliver a superior lubricating film. Formula 4-Stroke® Synthetic Oil also contains robust anti-wear additives that further reduce wear in metal-to-metal contact regions (see Four-Ball Wear Test graph).

 

Click on graph to see larger image

While automobile engines normally operate at around 2,500 rpm, outboard motors can run twice as fast, requiring greater levels of wear protection and better bearing durability than automobiles. In addition, prolonged idling and low operating temperatures contribute to fuel dilution, further thinning the oil. To ensure adequate protection for their engines, marine engine manufacturers set minimum high temperature/high shear (HTHS) viscosity limits. AMSOIL Formula 4-Stroke® Marine Synthetic Engine Oils are shear stable and formulated with sophisticated oil additive chemistry, exceeding the HTHS requirements of both the API and NMMA FC-W (see graph).

Excellent Anti-Rust Performance
Marine engines are prone to rust, leading to uncontrolled wear and premature engine failure. However, good rust protection is not natural to engine oil. It comes only by design. Formula 4-Stroke® Marine Synthetic Engine Oil is fortified with a special anti-rust agent, even more than required to pass stringent NMMA FC-W anti-rust testing.

Applications
AMSOIL Formula 4-Stroke® Marine Synthetic 10W-30 Engine Oil (WCT) is recommended for petrol fueled four-stroke outboard, inboard, inboard/outboard (I/O) and personal watercraft motors. AMSOIL WCT motor oil is recommended for the following applications whenever an SAE 5W-30, 10W-30 or straight SAE 30 oil is called for:

Four-stroke outboard motors: Honda®, Mercury®, Yamaha®, Johnson®/Evinrude®, Bombardier/BRP®, Suzuki®, Nissan®, Tohatsu®

Inboard and I/O: Mercruiser®, Volvo Penta®, OMC®, Chrysler® Marine, Crusader®, Marine Power®, Chevrolet®, Ford®

Personal Watercraft: Honda®, Yamaha®, Bombardier/BRP® (Sea-Doo®), Polaris®

Note: AMSOIL Formula 4-Stroke® Marine Synthetic 10W-30 is recommended for use in place of 5W-30 as specified by Honda®.

NMMA FC-W • API SL

Service Life

• Four-stroke outboard motors and personal watercraft applications: Due to potential fuel dilution or water contamination, change oil at the engine or watercraft manufacturer recommended interval.

• Inboard and I/O applications: Change oil at two times the engine manufacturer recommended interval or one year, whichever comes first.

Mixing AMSOIL
AMSOIL Formula 4-Stroke® Marine Synthetic Engine Oil is compatible with conventional and synthetic motor oils. Mixing AMSOIL motor oils with other oils will, however, shorten the oil life expectancy and reduce the performance benefits. AMSOIL does not support extended drain intervals where oils have been mixed.

Aftermarket oil additives are not recommended for use with AMSOIL motor oils.