Diesel engine oil for marine trunk piston engines. Mobilgard M430 is one of ExxonMobil's premium trunk medium speed engine oils with extra high performance. The Mobilgard M30 series is designed to meet the needs of engines operating on heavy fuel oil, and it has very good properties for engine cleanliness, especially in the crankcase, camshaft, ring belt, and piston crown.

SAE 40, Specific gravity at 15°C 0.915, Flash point 240 °C, Pour point -6 °C, Viscosity at 40°C 112 Cst, at 100°C 12.0 Cst, TBN 30, Sulfated ash content wt% 5.0.