Sierra Marine 18-9410-2 Full Synthetic SAE 30 4-Stroke Marine Engine Oil – FC-W Certified (1 Quart)

Sierra 18-9410-2 is a true 100% full-synthetic SAE 30 marine engine oil specifically developed for modern high-performance gasoline and diesel 4-stroke inboard and sterndrive engines. Its advanced synthetic base stocks and balanced additive package exceed NMMA FC-W requirements, delivering maximum protection against wear, corrosion, and thermal breakdown — even under extreme marine conditions.

This is the go-to oil when your engine manufacturer specifies a straight SAE 30 FC-W (common in many Yamaha, Honda, Suzuki, Yanmar diesel, and some Mercury/MerCruiser applications).

Key Features & Benefits

• 100% Full Synthetic formula — longer life and better performance than mineral or semi-synthetic oils
• NMMA FC-W Certified + meets/exceeds API CF & SL
• Recommended for both gasoline and diesel 4-stroke marine engines
• Superior wear protection during cold starts and high-load operation
• Outstanding corrosion protection — perfect for seasonal storage and saltwater use
• Reduces friction, oil consumption, and improves fuel economy
• Excellent thermal and oxidation stability — stays in grade longer
• Keeps engines cleaner with enhanced detergency

Specifications

• Viscosity: SAE 30 (straight grade)
• Type: Full Synthetic
• Volume: 1 U.S. Quart (0.946 L)
• Certifications: NMMA FC-W, API CF/SL
• Sold as: Single quart bottle

Commonly used in:

• Yamaha 4-stroke outboards calling for SAE 30
• Honda, Suzuki, and Tohatsu 4-strokes specifying SAE 30
• Many small marine diesels (Yanmar, etc.)
• Any 4-stroke marine engine where straight SAE 30 FC-W oil is recommended

(No manufacturer warranty — see Sierra’s standard terms)