HIGH VISCOSITY INDEX LUBRICATING OIL BASE STOCK VISCOSITY MODIFIER COMBINATIONS, AND LUBRICATING OILS DERIVED THEREFROM

摘要

A lubricating composition including a first base stock component including: one or more metallocene catalyzed polyalphaolefins (mPAOs), each mPAO having a kinematic viscosity (Kv100) from 40 cSt to 155 cSt and a viscosity index (VI) from 150 to 207; a second base stock including one or more polyalphaolefins (PAOs), each PAO having a kinematic viscosity (Kv100) less than 10 cSt and a VI from 130 to 145; and a viscosity modifier including a copolymer having units derived from monomers of (i) anα-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof esterified with an alcohol. A lubricant including the above lubricating composition. A method for improving fuel efficiency, while maintaining or improving wear control, load carrying capacity and/or traction reduction in a driveline device, e.g., gears and transmissions, lubricated with a lubricating oil, by using as the lubricating oil the above lubricant.