The use as an anti-wear additive and/or friction modifier in a non-aqueous lubricant composition and/or in a fuel composition of at least one long chain fatty acid ester of a hydroxy carboxylic acid in which the long chain fatty acid has at least 4 carbon atoms and the ester is an oil-soluble ester of a mono- or poly-hydroxy carboxylic acid having 1 to 4 groups which are independently carboxylic acid groups or lower hydrocarbyl esters thereof and in which, when the hydroxy carboxylic acid is a mono-hydroxy carboxylic acid, the ester has a long chain fatty acid ester moiety of the hydroxy group of the hydroxy carboxylic acid and, when the hydroxy carboxylic acid is a poly-hydroxy carboxylic acid, the ester has independently long chain fatty acid ester moieties of one or two of the hydroxy groups of the poly-hydroxy carboxylic acid. Also, a non-aqueous lubricant composition and a fuel composition for an internal combustion engine which comprises at least one of said long chain fatty acid esters.

The presently claimed invention is directed to novel polyesters which are obtainable by reacting a mixture comprising at least one C8-C20 Guerbet alcohol, at least one aliphatic or cycloaliphatic dicarboxylic acid and at least one polyol with a hydroxyl functionality in the range of ?2 to ?6 and the use of these polyesters as a component of lubricating oil compositions.

The presently claimed invention is directed to novel polyesters which are obtainable by reacting a mixture comprising at least one C8-C20 Guerbet alcohol, at least one aliphatic or cycloaliphatic dicarboxylic acid and at least one polyol with a hydroxyl functionality in the range of ?2 to ?6 and the use of these polyesters as a component of lubricating oil compositions.