Yamalube 20W-40 Full Synthetic 4M FC-W Marine Engine Oil – Gallon – LUB-20W40-FC-04 – OEM

Yamalube 20W-40 Full Synthetic 4M FC-W Marine Engine Oil – Gallon – LUB-20W40-FC-04 – OEM

Yamalube 20W-40 Full Synthetic 4M FC-W Marine Engine Oil is Yamaha’s premium marine-formulated lubricant engineered specifically for 4-stroke outboards operating under high-load, high-rpm conditions. Designed to meet and exceed NMMA® FC-W® certification standards, this advanced full synthetic formula provides superior protection against wear, corrosion, varnish, and sludge while maintaining viscosity stability in demanding marine environments.

Unlike automotive oil—formulated for engines typically cruising around 2,500 RPM—outboards commonly operate between 4,500 and 6,000 RPM for extended periods. That level of sustained stress can quickly break down conventional oils. Yamalube 4M FC-W is engineered to resist foaming, thermal breakdown, and moisture-related corrosion, delivering dependable protection during continuous throttle operation.

Why 20W-40?
20W-40 provides a thicker oil film at operating temperature compared to lighter viscosities like 10W-30. This makes it especially beneficial for high-temperature climates, sustained throttle use, and heavy-load applications where added film strength and shear stability are critical.

Viscosity: 20W-40
Certification: NMMA® FC-W®
Type: Full Synthetic 4-Stroke Marine Engine Oil (4M)
Size: Gallon
Genuine Yamaha OEM Product