Lubricating oil compositions comprising fischer-tropsch derived base oils

Abstract

Use of a lubricating oil composition comprising at least one Fischer-Tropsch derived base oil for reducing exhaust port blocking of a 2-stroke engine. The present invention also relates to a 2-stroke lubricating engine oil composition comprising (i) at least one Fischer-Tropsch derived base oil having a kinematic viscosity at 100° C. in the range of from 2 to 30 mm 2 /s at 100° C. and (ii) 5 wt % or greater of a hydrocarbon solvent; wherein the lubricating engine oil composition has a Blocking Index of greater than 130 as measured by the JASO M343-92 Exhaust System Blocking Test Method.

1 . A method comprising lubricating a 2-stroke engine with a lubricating oil composition comprising at least one Fischer-Tropsch derived base oil, wherein the lubricating oil composition provides reduced exhaust port blocking in the 2-stroke engine. 
     
     
         2 . The method of  claim 1  wherein the Fischer-Tropsch derived base oil has a kinematic viscosity at 100° C. in the range of from 2 mm 2 /s to 30 mm 2 /s. 
     
     
         3 . The method of  claim 1  wherein the Fischer-Tropsch derived base oil has a kinematic viscosity at 100° C. in the range of from 2 mm 2 /s to 10 mm 2 /s. 
     
     
         4 . The method of  claim 3  wherein the Fischer-Tropsch derived base oil has a kinematic viscosity at 100° C. in the range of from 2 mm 2 /s to 4 mm 2 /s. 
     
     
         5 . The method of  claim 1  wherein the Fischer-Tropsch derived base oil has a kinematic viscosity at 100° C. in the range of from 12 mm 2 /s to 30 mm 2 /s. 
     
     
         6 . The method of  claim 5  wherein the Fischer-Tropsch derived base oil has a kinematic viscosity at 100° C. in the range of from 18 mm 2 /s to 22 mm 2 /s. 
     
     
         7 . The method of  claim 5  wherein the lubricating oil composition comprises less than 2 wt % of a Fischer-Tropsch derived base oil having a kinematic viscosity at 100° C. in the range of from 2 mm 2 /s to 10 mm 2 /s. 
     
     
         8 . The method of  claim 1  wherein the lubricating composition comprises a first Fischer-Tropsch derived base oil having a kinematic viscosity at 100° C. in the range of from 2 mm 2 /s to 10 mm 2 /s and a second Fischer-Tropsch derived base oil having a kinematic viscosity at 100° C. in the range of from 12 mm 2 /s to 30 mm 2 /s. 
     
     
         9 . The method of  claim 8  wherein the weight ratio of the first Fischer-Tropsch derived base oil and the second Fischer-Tropsch derived base oil is in the range of from 10:1 to 1:5. 
     
     
         10 . The method of  claim 1  wherein the lubricating oil composition comprises 5 wt % or greater of a hydrocarbon solvent. 
     
     
         11 . The method of  claim 1  wherein the lubricating oil composition additionally comprises a smoke suppression agent selected from the group consisting of polybutene, polyisobutylene, and mixtures thereof. 
     
     
         12 . The method of  claim 1  wherein the lubricating oil composition additionally comprises a detergent/dispersant additive package. 
     
     
         13 . The method of  claim 1  wherein the lubricating composition additionally comprises a lubricity additive. 
     
     
         14 . A 2-stroke lubricating engine oil composition comprising (i) at least one Fischer-Tropsch derived base oil having a kinematic viscosity at 100° C. in the range of from 2 to 30 mm 2 /s and (ii) 5 wt % or greater of a hydrocarbon solvent; wherein the lubricating engine oil composition has a Blocking Index of greater than 130 as measured by the JASO M343-92 Exhaust System Blocking Test Method. 
     
     
         15 . A 2-stroke lubricating engine oil composition comprising (i) a first Fischer-Tropsch derived base oil having a kinematic viscosity at 100° C. in the range of from 2 mm 2 /s to 10 mm 2 /s and (ii) a second Fischer-Tropsch derived base oil having kinematic viscosity at 100° C. in the range of from 18 mm 2 /s to 30 mm 2 /s;
 wherein the weight ratio of the first Fischer-Tropsch derived base oil to the second Fischer-Tropsch derived base oil is in the range of from 10:1 to 1:5, and wherein the lubricating engine oil composition has a Blocking Index of greater than 130 as measured by the JASO M343-92 Exhaust System Blocking Test Method. 
 
     
     
         16 . The method of  claim 8  wherein the weight ratio of the first Fischer-Tropsch derived base oil and the second Fischer-Tropsch derived base oil is in the range of from 1.98:1 to 0.01:1. 
     
     
         17 . The method of  claim 1  wherein the lubricating engine oil composition has a Blocking Index of greater than 130 as measured by the JASO M343-92 Exhaust System Blocking Test Method. 
     
     
         18 . The 2-stroke lubricating engine oil composition of  claim 15  wherein the weight ratio of the first Fischer-Tropsch derived base oil and the second Fischer-Tropsch derived base oil is in the range of from 1.98:1 to 0.01:1.