Abstract: A lubricant composition especially adapted for use as an automatic transmission fluid, which composition consists essentially of: a) from 50 to 85 weight percent of a mineral oil having a viscosity at 100.degree. C. in the range of 3 to 5 centistokes; b) from 5 to 35 weight percent of a poly-.alpha.-olefin lubricating oil having a viscosity at 100.degree. C. in the range of 1 to 8 centistokes; and c) from 8 to 15 weight percent of a combination of alkenyl succinimide dispersant, viscosity index improver and antioxidant; said composition being further characterized in that it contains less than 7.0 weight percent of viscosity index improver and in that the composition has a Brookfield viscosity at -40.degree. C. of no more than 20,000 cP.

Abstract: An ashless or low-ash oleaginous liquid composition comprising a major amount of hydrogenated poly-.alpha.-olefin oligomer fluid having a viscosity in the range of about 2 to about 10 cSt at 100.degree. C., and minor amounts of at least the following: A) hydrogenated poly-.alpha.-olefin oligomer fluid having a viscosity in the range of about 40 to about 120 cSt at 100.degree. C.; and B) antiwear/extreme pressure agent selected from phosphorus-containing ashless dispersant, boron-containing ashless dispersant, and phosphorus- and boron-containing ashless dispersant. Compositions of this type can be formed having excellent high and low temperature viscosity characteristics and excellent shear stability. To this end, the preferred compositions are devoid or substantially devoid of conventional polymeric high molecular weight viscosity index improvers.

Abstract: An ashless or low-ash oleaginous liquid composition comprising a major amount of hydrogenated poly-.alpha.-olefin oligomer fluid having a viscosity in the range of about 2 to about 10 cSt at 100.degree.C., and minor amounts of at least the following: A) hydrogenated poly-.alpha.-olefin oligomer fluid having a viscosity in the range of about 40 to about 120 cSt at 100.degree.C.; and B) antiwear/extreme pressure agent selected from phosphorus-containing ashless dispersant, boron-containing ashless dispersant, and phosphorus- and boron-containing ashless dispersant. Compositions of this type can be formed having excellent high and low temperature viscosity characteristics and excellent shear stability. To this end, the preferred compositions are devoid or substantially devoid of conventional polymeric high molecular weight viscosity index improvers.