The key difference between Super Tractor Oil Universal (STOU) and Universal Tractor Transmission Oil (UTTO) is that STOU can be used as a tractor engine oil (up to API CF) as well as a transmission, final drive, wet brake and hydraulic fluid. Other than that, the two fluids are used in the same types of vehicles and equipment. Lubrizol is the premier supplier of STOU worldwide.
A STOU must provide:
✓ Engine protection
✓ Friction performance for clutches and wet brakes
✓ Gear protection for transmissions, axles and final drives
✓ Anti-wear protection
✓ Hydraulic pump durability
✓ Shear stability
✓ Oxidation resistance
✓ Corrosion protection
✓ Low temperature flow performance
Lubrizol's STOU performance packages are the most innovative in the industry. They have boosted soot control for reduced wear and viscosity increase; superior antiwear performance for reduced pitting and scoring in final drives; superior friction performance for transmission clutches and exceptional shiftability; viscosity modifiers to provide the desired viscosity grade; and exclusive manufacturer approvals.