VP Hi-Performance API GL-5 LS SAE 80w140 Gear Oil is semi-synthetic. It utilizes naturally high VI base stocks with a synthetic component and no viscosity index improvers. It features extreme pressure additives and rust and corrosion inhibitors for ultimate protection of gears and bearings. The result is outstanding load-carrying capacity and high-temperature protection. It provides limited slip performance, reducing chatter with improved traction, and helps extend component life. We recommend our 80W140 gear oil for heavy-duty axles and heavy-duty non-synchronized manual transmissions, as well as limited slip differentials.