10W30 4-STROKE MARINE ENGINE OIL Quicksilver’s all new 4-Stroke oil technology outperforms automotive oils in marine applications because of its specialized additive package designed for marine engines.  The NEW mineral 4-Stroke oil is also now approved for use in all outboard engines; previously only our synthetic blend could make this claim. 3 things to know: For use in all 4-Stroke Marine Engines – New formula 4-Stroke oils are engineering approved for use in certain marine 4-Stroke outboard applications and exceeds all Marine industry 4-Stroke oil requirements including FC-W and FC-W Catalyst Compatible.  In addition, all 10W30 & 25W40 oils are now fully FC-W Catalyst Compatible. Flagship engine and corrosion protection – industry leading strength and viscosity retention and ultimate corrosion and wear protection. The most recommended Marine Oil – Over 5 years of engineering and development by the larges marine engine manufacture in the world. 10W30 is recommended for certain operating temperatures and manual start applications.