The First In Synthetics

Motor Oil For Boaters


AMSOIL Stands up to tough marine conditions

NMMA Certified

The Right Choice For Outboards

Made For Marine Environment

Excellent anti-rust performance


Less likely to acidify and oxidize


Smoother running motors use less fuel

Trusted by Thousands

Specially Formulated for Marine Use

Extends Outboard Motor Life

Product Details and Specifications


We stand by our products


Fights Engine Wear
AMSOIL Synthetic Marine Engine Oil’s naturally strong base oils resist viscosity loss due to mechanical shear. It develops a tough lubricating film that protects engine parts, even in high-heat, high-rpm conditions that breakdown other oils. Synthetic Marine Engine Oil contains robust anti-wear additives that further reduce wear in metal-to-metal contact regions, guarding against compression loss for maximum power and engine life.

Excellent Anti-Rust Performance
Good rust protection is not natural to motor oil; it comes only by design. AMSOIL Synthetic Marine Engine Oil is fortified with potent inhibitors that guard against damaging rust and corrosion. It protects engines during use and during inactivity or long-term storage.

NMMA Certified
AMSOIL Synthetic Marine Engine Oil is certified by the National Marine Manufacturers Association (NMMA) for use in four-stroke outboard motors. This high-quality oil demonstrates outstanding performance and meets the requirements of the NMMA FC-W Catalyst Compatible specification, which is backward-compatible with the FC-W specification.

We stand by our products