A lubricant composition comprising (a) from 0.1 to 10 percent by weight of one or more polyalkylene glycols (PAG); and (2) one or more ester base oils selected from the group of natural esters, synthetic esters and combinations thereof; wherein the one or more PAG has a molecular weight in the range 1500 to 5000 g/mole, comprises from 10 to 40 percent by weight of units derived from ethylene oxide and from 90 to 60 percent by weight of units derived from propylene oxide; and wherein the one or more PAGs are in the form of block copolymer, reverse block copolymer or combinations thereof is provided. Also provided is a method of enhancing the hydrolytic stability of an ester base oil.

This thermally conductive grease composition contains a base oil, a thermally conductive filler, and calcium carbonate particles.

This thermally conductive grease composition contains a base oil, a thermally conductive filler, and calcium carbonate particles.

The present application concerns the use, for cooling and/or lubricating a propulsion system of an electric or hybrid vehicle, of an aqueous lubricating composition comprising at least: water and a polyalkylene glycol; the said aqueous lubricating composition comprising a phosphate ester salt(s) content of strictly less than 0.1% by mass, relative to the total mass of the said composition.

It also relates to the use of such an aqueous lubricant composition to reduce pitting by mechanical fatigue of the mechanical part(s) of an electric or hybrid vehicle propulsion system which is (are) brought into contact with the said composition.

Lastly, it relates to an aqueous lubricating composition for lubricating and/or cooling an electric or hybrid propulsion system, comprising: at least 45% by mass of water, relative to the total mass of the composition, and a polyalkylene glycol; the said composition comprising a phosphate ester salt(s) content of strictly less than 0.1% by mass, relative to the total mass of the said composition.