Mercury 8M0078630 – 25W‑40 Synthetic Blend 4‑Stroke Marine Engine Oil, 1 Gallon

OEM Mercury Marine oil for outboard, sterndrive, and inboard 4-stroke engines – premium wear, corrosion, and thermal protection in every gallon.

Product Overview

Mercury 8M0078630 is a 25W‑40 synthetic blend 4-stroke marine engine oil, formulated specifically for the demands of marine environments. Trusted by Mercury, MerCruiser, and other top engine manufacturers, this oil offers outstanding wear and corrosion protection, helping extend the life of your engine under extreme marine conditions.

This premium formulation maintains viscosity, resists varnish and sludge, and exceeds NMMA FC-W certification standards—outperforming conventional automotive oils thanks to a marine-specific additive package.

Key Features

• OEM-certified for all 4-stroke Mercury, MerCruiser, and other top marine engines
• 25W-40 viscosity for broad temperature stability and high-load performance
• FC-W certified – exceeds marine warranty requirements
• Prevents varnish buildup and sludge formation
• Superior rust and corrosion protection for saltwater and freshwater use
• Outperforms automotive oils in marine-specific conditions
• Packaged in a 1-gallon (3.78L) container for convenient service intervals

Engine Compatibility

For use in Mercury, MerCruiser and other leading brands of four-stroke outboard, sterndrive and inboard marine engines

Always refer to your owner’s manual for application-specific guidance.