Mercury-Mercruiser 10W-30 4-Stroke Synthetic Marine Oil The Mercury-Mercruiser 10W-30 4-Stroke Outboard Oil is formulated for engines that require FC-W Certified, SAE 10W-30 oil. Help maintain your peak engine performance and reliability. Reduce thermal breakdown under extreme loads, temperatures, and RPM. Exceeds oil requirements and FC-W Catalyst Compatible specifications for marine engine manufacturers. California Residents WARNING Cancer and Reproductive Harm - P65Warnings.ca.gov Other Detai