Abstract: The present invention relates to the use of a partly neutralized fatty amine salt where the fatty amine is having the formula where R is a hydrocarbyl group having 12-24 carbon atoms; X is H, a C1-C4 alkyl group, benzyl or —CH2CH2CH2NH2, m is 2 or 3 and n is 0-3, provided that when n is 0, then X IS —CH2CH2CH2NH2, and m is 3; and where the acid neutralizing the fatty amine has the formula R?COOH (II), where R?CO is an acyl group having 16-24 carbon atoms; and where the molar ratio between the moles of nitrogen atoms in the fatty amine and the moles of fatty acid is 5:1 to 1.25:1; as a friction modifier for a lubricating oil, especially for an internal combustion engine. The invention also relates to a lubricating oil composition comprising the partly acid neutralized product (I), and to a method for lubrication of interfacing mutually movable surfaces by bringing the surfaces into contact with the said lubricating oil.

Abstract: The present invention relates to the use of a partly neutralised fatty amine salt where the fatty amine is having the formula where R is a hydrocarbyl group having 12-24 carbon atoms; X is H, a C1-C4 alkyl group, benzyl or —CH2CH2CH2NH2, m is 2 or 3 and n is 0-3, provided that when n is 0, then X IS —CH2CH2CH2NH2, and m is 3; and where the acid neutralising the fatty amine has the formula R?COOH (II), where R?CO is an acyl group having 16-24 carbon atoms; and where the molar ratio between the moles of nitrogen atoms in the fatty amine and the moles of fatty acid is 5:1 to 1.25:1; as a friction modifier for a lubricating oil, especially for an internal combustion engine. The invention also relates to a lubricating oil composition comprising the partly acid neutralised product (I), and to a method for lubrication of interfacing mutually movable surfaces by bringing the surfaces into contact with the said lubricating oil.