Sierra 4 Stroke oil is specially formulated for the demands of marine and outboard engines. 10W-40 is a blend of premium grade synthetic and mineral oils with superior designed additives formulated for the extreme rigors of the marine environment.
These additives boost corrosion protection and lubrication. Outperforms standard 4-cycle automotive engine oils in marine applications, with excellent detergency, anti-oxidants, anti-wear, and corrosion protection.

The benefits for marine engines include reduced wear of internal components, corrosion protection for internal parts, cleaner pistons, and prevention of ring sticking. Excellent low temperature operating properties. Meets or exceeds quality performance API SJ, CF-4, CH-4. Recommended for use in all outboard manufacturers.