AMSOIL 25W-40 Synthetic Blend Marine Engine Oil

Description

AMSOIL 25W-40 Synthetic Blend Marine Engine Oil

Protects Against Wear

Marine engines face extreme operating conditions with high rpm sustained for long periods. For example, a boat cruising at 30 mph typically spins its engine around 5,000 rpm, compared to the roughly 2,000 rpm in a car at 60 mph. This intense stress can cause traditional automotive oils to degrade quickly and lose their effective thickness. AMSOIL 25W-40 Synthetic Blend Marine Engine Oil offers superior shear stability that keeps a steady lubricating film, shielding vital engine parts from wear and extending engine life.

Excellent Anti-Rust Performance

Constant exposure to wet, humid environments makes marine engines especially vulnerable to rust and corrosion. Rust acts like abrasive sandpaper inside the engine, damaging bearings, cylinder walls, piston rings, and aluminum components over time. These effects impair engine efficiency and can lead to serious failure.

Typical motor oils do not inherently provide strong rust defense; it requires intentional formulation. AMSOIL 25W-40 Synthetic Blend Marine Engine Oil includes powerful additives explicitly designed to prevent rust and corrosion.

• Handles high-stress, high-rpm operation without breaking down
• Enhanced protection against rust and corrosion

NMMA Certified

This oil meets the National Marine Manufacturers Association’s (NMMA) standards for four-stroke outboards, inboards, stern drives, and personal watercraft. It goes beyond the minimum NMMA “FC-W” (Four Cycle Water) requirements, demonstrating a reliable performance level.

• FC-W (CAT) Registration Number: FC-11825T

* All trademarked names belong to their respective companies without endorsement. Products here are engineered by AMSOIL for their specified uses.

Compared to Other Marine Engine Oils

In contrast to common brand-name marine oils like Quicksilver or Yamaha’s stock fluids, AMSOIL 25W-40 Synthetic Blend retains thicker, stable viscosity under prolonged high-rpm use. Many standard oils thin out faster, which increases wear risk and reduces rust protection in harsh marine settings.

APPLICATIONS

Ideal for gasoline-powered four-stroke inboards, outboards, inboards/outboards, and personal watercraft, including engines from Mercury* and Mercruiser* requiring these specifications:

• API SM
• NMMA FC-W Catalyst Compatible

SERVICE LIFE

For four-stroke outboards and PWCs, change intervals should follow the engine or watercraft manufacturer’s advice due to possible fuel or water contamination. For inboard and I/O engines, oil changes can be extended to twice the recommended interval or once yearly, whichever comes first.

WARRANTY

This oil maintains factory warranty coverage under Warranty Secure and is supported by AMSOIL’s Limited Warranty (G1363). See www.amsoil.com/warranty/ for details.

HEALTH & SAFETY

When used as directed and following the Safety Data Sheet (SDS) guidelines, this product poses no expected health risks. SDS is accessible online at www.amsoil.com or by request at (715) 392-7101. Keep away from children. Please recycle used oil and containers.