Compositions containing friction modifiers for continuously variable transmissions

A composition comprising:

• (a) an oil of lubricating viscosity;
• (b) about 2 to about 20 parts by weight of a shear stable viscosity modifier;
• (c) about 0.2 to about 1.5 parts by weight of an overbased metal salt;
• (d) about 0.14 to about 0.25 parts by weight of at least one phosphorus compound;
• and
• (e) about 0.15 to about 0.3 parts by weight of a combination of at least two friction modifiers, at least one of said friction modifiers being 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 amount of the friction modifier from said group being at least about 0.03 parts by weight.

A concentrate, capable of being diluted by addition of an oil of lubricating viscosity to form a composition suitable for use as an automatic transmission fluid, said concentrate comprising:

• (a) a concentrate-forming amount of an oil of lubricating viscosity;
• (b) a shear stable viscosity modifier in an amount which, upon said dilution, modifies the viscosity of said automatic transmission fluid;
• (c) an overbased metal salt in an amount of at least about 0.2 percent by weight, which amount, upon said dilution, contributes about 0.5 to about 10 Total Base Number to said automatic transmission fluid;
• (d) at least about 0.2 percent by weight of at least one phosphorus compound;
• and
• (e) at least about 0.2 percent by weight of a combination of at least two friction modifiers, at least one of said friction modifiers being 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 amount of the friction modifier from said group being at least about 0.06 percent by weight of the concentrate;
• provided that the total amount of the friction modifiers is limited to those amounts which provide a metal-to-metal coefficient of friction, upon said dilution of the concentrate, of at least 0.120 as measured at 110.degree. C. by ASTM-G-77.