A grease composition comprises a base oil and an aluminium complex soap thickener, with graphite, molybdenum di-sulphide, calcium carbonate and bismuth sulphide all included as additives. The composition exhibits advantageous load, wear and friction performance, especially in extreme pressure environments, and is particularly suitable for use on open gears.

A method for improving wear control of a steel surface lubricated with a lubricating oil through the generation of thick tribofilms. The method includes: (i) using as the lubricating oil a formulated oil, the formulated oil having a composition comprising at least one lubricating oil base stock as a major component; and at least one lubricating oil additive, as a minor component; and (ii) forming a tribofilm on the steel surface. In time-step tribofilm formation measurements of the lubricating oil by a mini-traction machine (MTM) at constant slide-to-roll ratio (SRR), the saturation traction coefficient (f.sub.s), which correlates to tribofilm thickness on the steel surface, is greater than about 0.11. In the method of this disclosure, elongation of timing chain due to wear of chain link pins is less than about 0.07%, as determined by Ford Chain Wear (FCW) test conducted in accordance with ILSAC GF-6 specification. The lubricating oils are useful in internal combustion engines.

A method for improving wear control of a steel surface lubricated with a lubricating oil through the generation of thick tribofilms. The method includes: (i) using as the lubricating oil a formulated oil, the formulated oil having a composition comprising at least one lubricating oil base stock as a major component; and at least one lubricating oil additive, as a minor component; and (ii) forming a tribofilm on the steel surface. In time-step tribofilm formation measurements of the lubricating oil by a mini-traction machine (MTM) at constant slide-to-roll ratio (SRR), the saturation traction coefficient (f.sub.s), which correlates to tribofilm thickness on the steel surface, is greater than about 0.11. In the method of this disclosure, elongation of timing chain due to wear of chain link pins is less than about 0.07%, as determined by Ford Chain Wear (FCW) test conducted in accordance with ILSAC GF-6 specification. The lubricating oils are useful in internal combustion engines.

A method of performing a cleanup service on an internal combustion engine. The method involves draining used fleet oil from the engine, filling the engine with cleanup oil, draining the cleanup oil after an operation interval, and filling the engine with fresh fleet oil. The method can be performed as a remedial measure for an engine already exhibiting high oil consumption, or as a preventative measure on a healthy engine.

A method of performing a cleanup service on an internal combustion engine. The method involves draining used fleet oil from the engine, filling the engine with cleanup oil, draining the cleanup oil after an operation interval, and filling the engine with fresh fleet oil. The method can be performed as a remedial measure for an engine already exhibiting high oil consumption, or as a preventative measure on a healthy engine.

A method for producing a renewable base oil from a feedstock of biological origin includes providing a feedstock, the feedstock including: 2-95 wt % of a mixture of free fatty acids; 5-98 wt % fatty acid glycerols selected from mono-glycerides, di-glycerides and tri-glycerides of fatty acids; 0-50 wt % of one or more compounds selected from the list consisting of: fatty acid esters of the non-glycerol type, fatty amides and fatty alcohols; a major part of the feedstock being a mixture of free fatty acids and fatty acid glycerols; subjecting all or part of the feedstock to ketonisation reaction conditions where two free fatty acids react to yield a ketone stream, and subjecting the ketone stream to both hydrodeoxygenation and to hydroisomerisation reaction conditions, to yield a deoxygenated and isomerised base oil product stream containing the renewable base oil.

A method for producing a renewable base oil from a feedstock of biological origin includes providing a feedstock, the feedstock including: 2-95 wt % of a mixture of free fatty acids; 5-98 wt % fatty acid glycerols selected from mono-glycerides, di-glycerides and tri-glycerides of fatty acids; 0-50 wt % of one or more compounds selected from the list consisting of: fatty acid esters of the non-glycerol type, fatty amides and fatty alcohols; a major part of the feedstock being a mixture of free fatty acids and fatty acid glycerols; subjecting all or part of the feedstock to ketonisation reaction conditions where two free fatty acids react to yield a ketone stream, and subjecting the ketone stream to both hydrodeoxygenation and to hydroisomerisation reaction conditions, to yield a deoxygenated and isomerised base oil product stream containing the renewable base oil.

Hydrotreatment of biological oil is disclosed for producing renewable base oil and a diesel oil from low value biological oils. Low value biological oils containing free fatty acids and fatty acid esters can be processed into a renewable base oil and a renewable diesel oil in an efficient manner by first separating at least part of the free fatty acids from the feedstock and then processing separately this free acid feed in a ketonisation reaction followed by hydrodeoxygenation and hydroisomerisation reactions to yield a renewable base oil stream. The remaining free fatty acid depleted feed is processed in a separate hydrodeoxygenation and hydroisomerisation step to yield a renewable diesel stream.

Hydrotreatment of biological oil is disclosed for producing renewable base oil and a diesel oil from low value biological oils. Low value biological oils containing free fatty acids and fatty acid esters can be processed into a renewable base oil and a renewable diesel oil in an efficient manner by first separating at least part of the free fatty acids from the feedstock and then processing separately this free acid feed in a ketonisation reaction followed by hydrodeoxygenation and hydroisomerisation reactions to yield a renewable base oil stream. The remaining free fatty acid depleted feed is processed in a separate hydrodeoxygenation and hydroisomerisation step to yield a renewable diesel stream.

A C.sub.31 renewable base oil is disclosed that is suitable as a base oil to provide low viscosity base oils, such as having both low Noack volatility and low CCS-30 C. viscosity and/or to provide low viscosity base oils at the same time having a combination of acceptable HTHS and KV100 to allow the industry's base oil blenders to formulate high quality engine oils, such as SAE grade 0W-20, 0W-16, 0W-12 or 0W-8.