UNEXPECTED SHEAR STABILITY BENEFITS OF SYNTHETIC OILS AND VISCOSITY MODIFIER COMBINATIONS

摘要

In one embodiment, a lubricating oil with favorable shear stability is disclosed. The lubricating oil comprising a major amount of base stock selected from the group consisting of Group II, Group III, Group IV, Group V, and any combination thereof, a viscosity index improver comprising a polymethacrylate with a permanent shear stability index of less than 45 defined by ASTM 5621 with 10 percent polymer in a Group I mineral oil, an antioxidant additive and a corrosion additive. In a second embodiment a method of improving shear stability is disclosed. In a third embodiment, a method of blending an oil to provide improved shear stability and favorable viscosity index is disclosed.