Engineered synthetic engine oil and method of use
AssigneePrimrose Oil Company
InventorEdward Alan Paul
Life of this patent
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Abstract
A synthetic lubricant for gasoline and diesel engines having a viscosity ranging between about 14.5 and 16.5 cs at 100° C., the lubricant containing from about 55 to about 75 volume percent polyalphaolefin having a viscosity of about 6 to 8 cs at 100° C., an ethylene-propylene copolymer, an ester or diester, a packaged additive, a total base number enhancer and a minor effective amount of an antifoamant. A method of use is also provided whereby the subject lubricant is recirculated through an operating engine while periodically monitoring the total base number and adjusting the total base number to a level of about 12.0 by the addition of a total base number enhancer such as calcium phenate.
Claims36
An engine lubricant comprising from about 55 to about 75 volume percent polyalphaolefin having a viscosity between about 6 and 8 centistokes at 100° C.;
- from about 5 to about 10 volume percent of a compound that is compatible with the polyalphaolefin and is selected from esters and diesters having a viscosity of at least about 3.5 cs at 100° C.;
- a sufficient amount of an ethylene-propylene copolymer having a shear stability index of at least about 25 to produce a resultant lubricant viscosity ranging from about 14.5 to about 16.5 cs at 100° C.;
- and sufficient total base number enhancer to raise the total base number of the resultant lubricant to at least 10.
An engine lubricant comprising from about 60 to about 70 volume percent of a polyalphaolefin copolymer of decene and dodecene having a viscosity of about 7 cs at 100° C.;
- from about 5 to about 10 volume percent of a compound consisting of an ester or diester that is compatible with the polyalphaolefin;
- a sufficient amount of an ethylene-propylene copolymer having a shear stability index of at least about 25 to produce a viscosity in the resultant lubricant ranging from about 14.5 to about 16.5 cs at 100° C.;
- a sufficient amount of a commercially available lubricating oil additive package to bring the resultant lubricant into compliance with SAE 5W40 specifications;
- and sufficient total base number extender to produce a total base number of at least 10 in the resultant lubricant.
A method for lubricating an engine, comprising the steps of providing an engine with an oil recirculation system;
- filling the oil recirculation system to an operational level with a full PAO synthetic engine oil having a viscosity ranging from about 14.5 to about 16.5 cs at 100° C., said engine oil comprising from about 55 to about 75 volume percent polyalphaolefin having a viscosity from about 6 to about 8 cs. at 100° C. and having an initial total base number ranging between about 10 and about 12.5;
- operating the engine while recirculating the engine oil;
- periodically monitoring the total base number of the engine oil to determine whether the total base number of oil has dropped below 10;
- and adding to the engine oil a sufficient amount of a total base number enhancer to raise the total base number to a level above 10.
Dependencies are inferred from the claim text.