Compositions containing friction modifiers for continuously variable transmissions

摘要

A composition comprising of an oil of lubricating viscosity; a shear stable viscosity modifier; at least 0.1 percent by weight of an overbased metal salt; at least 0.1 percent by weight of at least one phosphorus compound; and 0.1 to 0.25 percent by weight of a combination of at least two friction modifiers provides an improved fluid for continuously variable transmissions. At least one of the friction modifiers is selected from the group consisting of zinc salts of fatty acids having at least 10 carbon atoms, hydrocarbyl imidazolines containing at least 12 carbon atoms in the hydrocarbyl group, and borated epoxides. The total amount of the friction modifiers is limited to those amounts which provide a metal-to-metal coefficient of friction of at least about 0.120 as measured at 110 DEG C. by ASTM-G-77.