Sierra 18-9421CAT-3 10W-30 Synthetic Blend 4-Stroke Outboard Engine Oil 1 Gallon

Sierra 18-9421CAT-3 is a premium synthetic blend 10W-30 engine oil specifically formulated for modern 4-stroke marine engines. This advanced formula is designed to meet the demanding requirements of recreational marine engines with or without emission catalyst systems, providing comprehensive protection for your investment.

Key Features:

• NMMA FC-W Certified and exceeds FC-W Cat Compatible specifications for catalyst-equipped engines
• Approved for all 4-stroke marine applications including outboard, sterndrive, and inboard engines
• Advanced ZDDP (Zinc Dialkyl Dithiophosphate) anti-wear additive technology for superior engine protection
• Prevents phosphorous depletion to extend emission catalyst life and maintain optimal performance
• Industry-leading wear protection and deposit control keeps engines running cleaner longer
• Superior corrosion protection designed for extreme marine environments
• Recommended for Mercury 4-Cycle outboard engines requiring 10W-30 viscosity

This synthetic blend formula combines the performance benefits of synthetic base stocks with the proven protection of premium mineral oils, delivering exceptional lubrication across a wide temperature range. The specialized additive package provides outstanding protection against rust, corrosion, and wear while maintaining compatibility with modern catalyst emission systems. Each gallon container is sold as part of a case pack.