Multi-grade engine oil formulations with improved mini-rotary viscometer results

摘要

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.

主权项

1. A multigrade engine oil comprising:
a) a first base oil, comprising: at least about 55 wt % of molecules having paraffinic functionality, at least about 25 wt % of molecules having cycloparaffinic functionality, a ratio of weight percent molecules with paraffinic functionality to weight percent of molecules with cycloparaffinic functionality of about 2, a boiling range between about 359 to 490° C., a VI between about 96 to 106, a flash point between about 190 to 228° C., a kinematic viscosity between about 3.0 to 7.0 cSt at 100° C., and a kinematic viscosity between about 24 to 34 cSt at 40° C.; b) a second base oil; and c) an additive package, wherein the multigrade engine oil comprises between about 30 to 50 wt % of the first base oil and about 10 to 30 wt % of the second base oil and the multigrade engine oil has a MRV at −30° C. of less than 50,000 and no yield stress, a Noack volatility of less than about 15 wt %; a Scanning Brookfield Viscosity between about 40,000 to 50,000 cP; and a Pour Point between about −39 to −46° C.