Sierra 18-9555CAT-4 Semi-Synthetic 5W-30 Marine Engine Oil 4-Case Pack (5 Quart Bottles)

The Sierra 18-9555CAT-4 is a semi-synthetic ultra-high-performance marine engine oil specifically formulated for non-turbo inboard engines equipped with catalytic converters. This 4-case pack includes four 5-quart bottles of 5W-30 viscosity oil, utilizing premium base stocks combined with industry-leading additive technology to deliver superior protection and performance in demanding marine environments.

Advanced Catalyst Protection:

• Features advanced ZDDP (Zinc Dialkyl Dithiophosphate) additive technology that prevents phosphorus depletion, extending the life of your engine's catalytic converter
• Meets and exceeds both FC-W Catalyst and FC-W marine oil specifications
• Meets or exceeds API SM category requirements for four-stroke gasoline engines

Superior Engine Protection:

• Enhanced detergent package actively suspends contaminants and prevents harmful sludge buildup
• Reduces internal friction to maintain peak engine performance and fuel efficiency
• Prevents thermal and oxidation breakdown even under extreme operating temperatures
• High shear stability maintains proper viscosity and prevents excessive oil thinning in high-performance applications

Application: Designed specifically for non-turbocharged inboard marine engines with catalytic converter systems. Ideal for gasoline-powered boats requiring FC-W Catalyst compatible oil.

Each case contains four 5-quart bottles, providing 20 quarts total for multiple oil changes or fleet maintenance.