Cold Cranking Simulator Viscosity Boosting Base Stocks and Lubricating Oil Formulations Containing the Same

Abstract

This disclosure relates to cold cranking simulator viscosity (“CCSV”) boosting base stocks that allow flexibility for engine oil formulations to meet both high and low temperature viscosity requirements while maximizing fuel efficiency. The CCSV-boosting base stocks can include C28-C60 hydrocarbon materials, linear esters, tertiary amides, dialkyl carbonates, aromatic alcohols, and aromatic ethers. This disclosure also relates to lubricating oil formulations containing the CCSV-boosting base stocks, and a method for improving fuel efficiency in an engine by using as the engine oil a lubricating oil formulation containing one or more of the CCSV-boosting base stocks and/or cobase stocks.

What is claimed is: 
     
         1 . A method for determining boosting efficacy of a first base stock in boosting the cold crank simulator viscosity at a given temperature as determined pursuant to ASTM D5293 (“CCSV”) of a lubricating oil formulation comprising the first base stock and a reference oil, the method comprising:
 determining the kinematic viscosity at 100° C. as determined pursuant to ASTM D2245 (“KV100”) of the reference oil; 
 determining the CCSV of the reference oil; 
 determining the KV100 of a mixture oil consisting of the first base stock and the reference oil at a first concentration of the first base stock based on wthe total quantity of the mixture oil; 
 determining the CCSV of the mixture oil; and 
 determining the first base stock as not a CCSV-boosting base stock if the CCSV of the mixture oil is smaller than the CCSV of the reference oil. 
 
     
     
         2 . The method of  claim 1 , further comprising:
 recording the KV100 and CCSV of the reference oil as KV100(ref) and CCSV(ref), respectively;   recording the KV100 and CCSV of the mixture oil as KV100(oil) and CCSV(oil), respectively;   determining the following values D(kv) and D(ccsv):
     D (kv)=100×(KV100(oil)−KV100(ref))/KV100(ref);
 
     D (ccsv)=100×(CCSV(oil)−CCSV(ref))/CCSV(ref); and
 
   determining the boosting efficacy of the first base stock at the first concentration based on D(kv) and D(ccsv).   
     
     
         3 . The method of  claim 1 , further comprising:
 determining the base stock as a CCSV-boosting base stock at the first concentration if the KV100 of the mixture oil is smaller than the KV100 of the reference oil, and the CCSV of the mixture oil is larger than the CCSV of the reference oil.   
     
     
         4 . The method of  claim 2 , further comprising:
 determining the base stock as a CCSV-boosting base stock at the first concentration if D(kv)>0, D(ccsv)>0, and D(ccsv)/D(kv)≥4.0.   
     
     
         5 . The method of  claim 2 , further comprising:
 determining the base stock as not a CCSV-boosting base stock at the first concentration if D(kv)>0, and D(ccsv)/D(kv)<4.0.   
     
     
         6 . The method of  claim 3 , further comprising:
 determining the first base stock as a superior CCSV-boosting base stock at the first concentration if D(ccsv)≥5.0.   
     
     
         7 . The method of  claim 6 , further comprising:
 determining the first base stock as an overall superior CCSV-boosting base stock if the first base stock is a superior CCSV-boosting base stock at a concentration of 5 wt % thereof based on the total weight of the first base stock and the reference oil.   
     
     
         8 . The method of  claim 1 , wherein:
 the lubricating oil formulation comprises an API Group III base stock and/or a Group IV base stock, the Group III base stock and Group IV base stock being different from the first base stock.   
     
     
         9 . The method of any of  claim 1 , wherein:
 the reference oil comprises an API Group III base stock and/or a Group IV base stock, the Group III base stock and Group IV base stock being different from the first base stock.   
     
     
         10 . The method of  claim 1 , wherein:
 the reference oil is the remainder of the lubricating oil formulation absent the first base stock and absent all additive components.   
     
     
         11 . The method of  claim 1 , wherein:
 the reference oil comprises a mixture of all base stocks in the lubricating oil formulation other than the first base stock.   
     
     
         12 . The method of  claim 1 , wherein:
 the reference oil comprises a base stock in the lubricating oil formulation having a CCSV that is closest to the CCSV of the first base stock among all base stocks contained in the lubricating oil formulation other than the first base stock.   
     
     
         13 . The method of  claim 1 , wherein:
 the reference oil comprises a base stock in the lubricating oil formulation having a KV100 that is closest to the KV100 of the first base stock among all base stocks contained in the lubricating oil formulation other than the first base stock.   
     
     
         14 . The method of  claim 1 , wherein:
 the lubricating oil formulation consists of the reference oil and the first base stock.   
     
     
         15 . A method for making a lubricating oil formulation, comprising:
 providing a reference oil with a kinematic viscosity at 100° C. as determined pursuant to ASTM D2245 (“KV100”) of KV100(ref) and cold crank simulator viscosity at a given temperature as determined pursuant to ASTM 5293 (“CCSV”) of CCSV(ref);   providing a first base stock having a CCSV of CCSV(b), where CCSV(b)>CCSV(ref);   such that when mixing the reference oil and the first base stock to obtain a mixture oil having a KV100 of KV100(oil) and a CCSV of CCSV(oil), one of the conditions (i) and (ii) below is met:   (i) D(kv)<0 and D(ccsv)≥1; and   (ii) D(kv)≥0, D(ccsv)≥5, and D(ccsv)/D(kv)≥4.0; where
     D (kv)=100×(KV100(oil)−KV100(ref))/KV100(ref); and
 
     D (ccsv)=100×(CCSV(oil)−CCSV(ref))/CCSV(ref).
 
   
     
     
         16 . The method of  claim 15 , further comprising:
 providing additional components;   mixing the additional components with the first base stock and the reference oil to obtain the lubricating oil formulation.   
     
     
         17 . The method of  claim 15 , wherein:
 the reference oil comprises an API Group III and/or Group IV base stock, the Group III base stock and Group IV base stock being different from the first base stock.   
     
     
         18 . The method of  claim 15 , wherein:
 the reference oil comprises an API Group IV base stock having a KV100 in the range from 3.0 to 15.0 cSt.   
     
     
         19 . The method of  claim 15 , wherein:
 the reference oil comprises a base stock in the lubricating oil formulation having a CCSV that is closest to the CCSV of the first base stock among all base stocks contained in the lubricating oil formulation other than the first base stock.   
     
     
         20 . The method of  claim 15 , wherein:
 the reference oil comprises a base stock in the lubricating oil formulation having a KV100 that is closest to the KV100 of the first base stock among all base stocks contained in the lubricating oil formulation other than the first base stock.   
     
     
         21 . The method of  claim 15 , wherein:
 the reference oil comprises an API Group IV base stock having a KV100 in a range from 3.0 to 8.0 cSt.   
     
     
         22 . The method of  claim 15 , wherein:
 the lubricating oil formulation is free of the reference oil; and   the lubricating oil formulation comprises a second base stock having a KV100 within the range from 0.50*KV100(ref) to 2.0*KV100(ref), where the second base stock is in the same API Group as the reference oil.