Valvoline STOU SAE 10W-40 is a premium Super Tractor Oil Universal (STOU) that provides complete multi-system lubrication for agricultural tractors and farm machinery in a single, versatile product. Designed to meet the requirements for engine oil, transmission fluid, hydraulic oil, differential lubricant, and wet brake fluid simultaneously, this STOU eliminates the need for multiple specialized products and simplifies maintenance for farming operations of all sizes.

The 10W-40 viscosity grade strikes an optimal balance between cold-weather fluidity and high-temperature protection. It flows readily at low temperatures for quick startups and immediate system pressurization during cool mornings, while maintaining a strong protective oil film under the heavy loads and elevated temperatures encountered during intensive field work. This wide viscosity range makes it an excellent year-round choice in most agricultural climates.

Formulated with premium base oils and a state-of-the-art additive package, Valvoline STOU 10W-40 provides outstanding anti-wear protection for heavily loaded gears and bearings, consistent and chatter-free wet brake operation, responsive hydraulic system performance with excellent seal compatibility, and robust corrosion protection during both active use and seasonal equipment storage.

The oil's carefully calibrated friction characteristics ensure smooth clutch engagement and reliable power take-off (PTO) operation across varying conditions. Approved by many leading tractor manufacturers, STOU 10W-40 is compatible with equipment from AGCO, Claas, Fendt, John Deere, Ford New Holland, Massey Ferguson, and other major brands. It is the ideal solution for modern farming operations seeking to consolidate lubricant inventory, reduce maintenance complexity, and ensure reliable equipment performance throughout the year.