Prime Guard QUIK78623 25W-40 Synthetic Blend 4-Stroke Marine Engine Oil 1 Gallon

The Prime Guard QUIK78623 is a 25W-40 synthetic blend 4-stroke marine engine oil sold in a convenient one-gallon bottle. This product cross-references to Mercury/Quicksilver OEM part number 8M0078623 and is formulated specifically for the demands of marine environments — where standard automotive oils fall short.

This catalyst-compatible synthetic blend is engineered using premium-grade base stocks combined with specially designed marine additives that provide superior moisture resistance, rust protection, and outstanding wear protection for trouble-free operation on the water.

Key Features:

• Synthetic Blend Formula: Combines premium mineral and synthetic base stocks for enhanced protection and viscosity stability across operating temperatures
• 25W-40 Viscosity: Delivers reliable cold-start performance and maintains viscosity under high-load, high-temperature cruising conditions
• FC-W & FC-W Catalyst Compatible: Exceeds all marine industry 4-stroke oil requirements including NMMA FC-W certification
• Corrosion & Wear Protection: Cleaning additives and inhibitors reduce scuffing and scoring of pistons and cylinder walls to extend engine life
• Broad Marine Application: Suitable for 4-stroke outboard, sterndrive (I/O), and inboard marine engines
• 1-Gallon Bottle: Ideal volume for routine oil changes on most marine engines

Cross-reference OEM part number: 8M0078623 / 92-8M0078623. This oil meets or exceeds manufacturer warranty requirements for FC-W marine engine oil and provides the superior moisture and rust protection that marine engines demand.