A high quality, multifunctional, extreme pressure fluid to meet the service top up and refill needs of transmissions, final drives, hydraulic and power-steering systems and fluid immersed disc brakes of virtually all farm and industrial tractors and mobile equipment, especially where many components must be satisfied with a fluid from a common source. Engol tractor transmission oil has a high viscosity index to minimise viscosity changes with changing temperatures. It is extremely stable even in severe high temperature torque converter use and has excellent anti wear properties. Frictional properties are designed to assure proper, decisive functioning of multi disc clutches used in some transmission designs requiring a limited slip function and in oil immersed disc brakes.