ALL-WEATHER TRACTOR HYDRAULIC FLUID USING A MIXTURE OF VISCOSITY MODIFIER TYPES TO MEET SHEAR-STABLE MULTIGRADE VISCOSITY REQUIREMENTS

摘要

A composition of the following components: an oil of lubricating viscosity; a polymethacrylate viscosity modifier; an ester of a maleic acid/styrene copolymer; and optionally, an additive package that imparts to the fluid the capacity to meet bench and dynamometer tests specified by an equipment manufacturer, is suitable for use as a functional fluid such as a tractor hydraulic fluid, under a wide variety of climatic conditions.