Engine Oil Compositions with Improved Fuel Economy Performance

Abstract

An engine lubricating oil exhibiting a fuel economy improvement is disclosed. The engine oil composition meets at least one of ILSAC GF-4, API CI-4, API CJ4, ACEA A1, ACEA A5, ACEA B1, ACEA B5, ACEA C1, ACEA C2, ACEA C3, ACEA C4A, and JASO DL-1 performance specifications. The composition comprises at least an isomerized base oil comprising a consecutive number of carbon atoms and having a CCS Viscosity at −35° C. of less than or equal to 7000 mPa, a T 95 -T 5 boiling range distribution of less than or equal to 200° C., a ratio of weight percent molecules with monocycloparaffinic functionality to weight percent molecules with multicycloparaffinic functionality of greater than 15, and an Oxidator BN of greater than 30 hours; and 0.05 to 40 wt %. of at least an additive selected from the group of metal detergents, dispersants, wear inhibitors, anti-oxidants, friction modifiers, viscosity modifiers, corrosion inhibitors, seal swelling agents, metal deactivators, anti-foamants, and mixtures thereof.

1 . An engine oil composition meeting at least one of ILSAC GF-4, API CI-4, API CJ4, ACEA A1, ACEA A5, ACEA B1, ACEA B5, ACEA C1, ACEA C2, ACEA C3, ACEA C4A, and JASO DL-1 performance specifications, the composition comprising:
 at least an isomerized base oil comprising a consecutive number of carbon atoms and having a CCS Viscosity at −35° C. of less than or equal to 7000 mPa, a T 95 -T 5  boiling range distribution of less than or equal to 200° C., a ratio of weight percent molecules with monocycloparaffinic functionality to weight percent molecules with multicycloparaffinic functionality of greater than 15, and an Oxidator BN of greater than 30 hours; and   0.05 to 40 wt %. of at least an additive selected from the group of metal detergents, dispersants, wear inhibitors, anti-oxidants, friction modifiers, viscosity modifiers, corrosion inhibitors, seal swelling agents, metal deactivators, anti-foamants, and mixtures thereof.   
     
     
         2 . The engine oil composition of  claim 1 , wherein the composition meets ILSAC GF-4 performance specification. 
     
     
         3 . The engine oil composition of  claim 1 , where the composition contains less than 0.3 wt. % of a friction modifier. 
     
     
         4 . The engine oil composition of  claim 2 , wherein the composition meets ILSAC GF-4 performance specification and wherein the composition does not contain any added friction modifier. 
     
     
         5 . The engine oil composition of  claim 1 , wherein the composition exhibits a fuel economy improvement of greater than or equal to 1% compared to an engine oil composition employing a non-isomerized base oil, wherein the fuel economy improvement is measured by summing Stage-4 and Stage-5 Phase I Sequence VIB Screener Test results. 
     
     
         6 . The engine oil composition of  claim 5 , wherein the fuel economy improvement of greater than or equal to 1.5%. 
     
     
         7 . The engine oil composition of  claim 6 , wherein the fuel economy improvement of greater than or equal to 1.75%. 
     
     
         8 . The engine oil composition of  claim 1 , wherein the isomerized base oil has an Oxidator BN of at least 35 hours. 
     
     
         9 . The engine oil composition of  claim 1 , wherein the isomerized base oil has an Oxidator BN of at least 50 hours. 
     
     
         10 . The engine oil composition of  claim 1 , wherein the isomerized base oil has a viscosity index of at least 135. 
     
     
         11 . The engine oil composition of  claim 10 , wherein the isomerized base oil has a viscosity index of at least 140. 
     
     
         12 . The engine oil composition of  claim 1 , wherein the isomerized base oil is a Fischer-Tropsch derived base oil made from a waxy feed. 
     
     
         13 . The engine oil composition of  claim 1 , wherein isomerized base oil has an average degree of branching in the molecules between 6.5 and 10 alkyl branches per 100 carbon atoms. 
     
     
         14 . The engine oil composition of  claim 1 , wherein the isomerized base oil has a wt % Noack volatility between 0 and 100. 
     
     
         15 . The engine oil composition of  claim 1 , wherein the isomerized base oil has an auto-ignition temperature (AIT) greater than an amount defined by: 1.6×(Kinematic Viscosity at 40° C., in mm 2 /s)+300. 
     
     
         16 . The engine oil composition of  claim 1 , wherein the isomerized base oil has a total weight percent of molecules with cycloparaffinic functionality of greater than 10. 
     
     
         17 . The engine oil composition of  claim 14 , wherein the isomerized base oil is made from a process in which the highly paraffinic wax is hydroisomerized using a shape selective intermediate pore size molecular sieve comprising a noble metal hydrogenation component, and under conditions of about 600° F. to 750° F. and wherein the isomerized base oil has a Noack volatility of less than 50 weight %. 
     
     
         18 . The engine oil composition of  claim 14 , wherein the isomerized base oil comprises greater than 3 weight % molecules with cycloparaffinic functionality and less than 0.30 weight percent aromatics. 
     
     
         19 . The engine oil composition of  claim 14 , wherein the isomerized base oil has a traction coefficient of less than 0.023 when measured at a kinematic viscosity of 15 mm 2 /s and at a slide to roll ratio of 40%. 
     
     
         20 . The engine oil composition of  claim 1 , wherein the engine oil composition exhibits an MRV of less than or equal to 12,000 mPa at −40° C. 
     
     
         21 . The engine oil composition of  claim 20 , wherein the engine oil composition exhibits an MRV of less than or equal to 8,800 mPa at −40° C. 
     
     
         22 . The engine oil composition of  claim 21 , wherein the engine oil composition exhibits an MRV of less than or equal to 7,330 mPa at −40° C. 
     
     
         23 . The engine oil composition of  claim 1 , wherein the engine oil composition exhibits a CCS Viscosity at −35° C. of less than or equal to 1400 mPa. 
     
     
         24 . The engine oil composition of  claim 22 , wherein the engine oil composition exhibits a CCS Viscosity at −35° C. of less than or equal to 1200 mPa.