A stable colloidal suspension comprising: (a) a dispersed phase comprising a major amount of one or more dispersed hydrated polymeric compounds selected from the group consisting of polymolybdates, polytungstates, polyvanadates, polyniobates, polytantalates, polyuranates, and mixtures thereof, and, (b) an oil phase comprising one or more dispersing agents and a diluent oil. Processes for preparing the stable colloidal suspensions and their use in lubricating oil compositions are also provided.