Base oil blend upgrading process with a group ii base oil to yield improved mini-rotary viscometer results

Abstract

A process for improving MRV performance and decreasing wax crystallization in a lubricating oil, comprising: replacing between about 5 to 60 wt % of a base oil or base oil blend with between about 5 to 60 wt % of a Group II base oil. A resultant multigrade engine oil affords a Mini-Rotary Viscosity (MRV) at −30° C. of less than 60,000 mPa·s with no yield stress. The multigrade engine oil, comprising: (a) between about 10 to 30 wt % of a Group II base oil and (b) between about 40 to 60 wt % of a Group I paraffinic base oil characterized by: (i) a VI from about 98 to 104, and (ii) a kinematic viscosity from about 4.5 to 5.5 cSt at 100° C., and (c) an additive package.

Dependencies are inferred from the claim text.