Synthetic lubricating compositions

摘要

Lubricating oil compositions of the invention comprise a major amount of a base oil of lubricating viscosity and an effective amount of at least one lubricant antioxidant, the base oil comprising a blend of a Group III base oil derived from a synthesis gas, and a Group IV base oil wherein the ratio of the Group III to Group IV base oils is such that the lubricating composition exhibits an oxidation stability determined by a measure of high temperature deposits that is less than half the mathematical sum of the oxidative stability determined for each of the unblended Group III and Group IV oils containing the same antioxidant in the same amount as in the blend.