Valvoline STOU SAE 15W-40 is a premium Super Tractor Oil Universal (STOU) engineered to provide comprehensive lubrication for all major tractor systems from a single product. This multifunctional oil satisfies the requirements for engine lubrication, manual and powershift transmissions, differentials and final drives, hydraulic systems, and wet brakes, making it the ideal all-in-one solution for agricultural and light industrial equipment.

The 15W-40 viscosity grade delivers a robust oil film that provides superior protection under heavy loads and elevated operating temperatures, making it particularly well-suited for high-horsepower tractors and demanding field operations during warmer months. This formulation maintains excellent thermal stability during prolonged, high-output work such as tillage, harvesting, and heavy hauling, ensuring consistent protection throughout extended operating periods.

Valvoline STOU is built with premium base oils and an advanced additive system that provides exceptional anti-wear protection for heavily loaded gear sets, smooth and predictable wet brake performance, reliable hydraulic system operation with minimal internal leakage, and strong corrosion inhibition for equipment stored during off-season periods. The carefully tuned friction modifiers ensure proper clutch engagement and PTO operation, preventing slippage while maintaining smooth, chatter-free performance.

This STOU is approved by many leading tractor manufacturers and is suitable for use in equipment from brands such as John Deere, Ford New Holland, Massey Ferguson, AGCO, Claas, and Fendt. By consolidating multiple lubricant needs into one product, STOU 15W-40 helps farming operations reduce inventory costs, prevent cross-contamination errors, and streamline maintenance procedures across their equipment fleet.