A process for preparing an overbased alkali metal alkylhydroxybenzoate, said process comprising overbasing an alkali metal alkylhydroxybenzoate or a mixture of alkali metal alkylhydroxybenzoate and up to 50 mole % of alkylphenol, based on the total mixture of alkylhydroxybenzoate and alkylphenol, with a molar excess of alkaline earth metal base and at least one acidic overbasing material in the presence of at least one carboxylic acid having from one to four carbon atoms and a solvent selected from the group consisting of aromatic hydrocarbons, aliphatic hydrocarbons, monoalcohols and mixtures thereof.