In some embodiments, ethylene-propylene random copolymers as viscosity modifiers were synthesized with pyridyldiamido catalyst systems and a chain transfer agent. In some embodiments, the present disclosure provides for ethylene-propylene random copolymers having an ethylene content between about 45 wt % and about 55 wt %. In some embodiments, the ethylene-propylene random copolymer is used as a viscosity modifier in a lubricating composition and a fuel composition.

In some embodiments, ethylene-propylene random copolymers as viscosity modifiers were synthesized with pyridyldiamido catalyst systems and a chain transfer agent. In some embodiments, the present disclosure provides for ethylene-propylene random copolymers having an ethylene content between about 45 wt % and about 55 wt %. In some embodiments, the ethylene-propylene random copolymer is used as a viscosity modifier in a lubricating composition and a fuel composition.

A composition with a kinematic viscosity for cooling and lubricating a drive system of an electric or hybrid vehicle, measured at 100 C. in accordance with the standard ASTM D445, in the range 3 to 10 mm.sup.2/s. The composition includes 70% to 90% of a base oil or a mixture of base oils having a kinematic viscosity, measured at 100 C. in accordance with the standard ASTM D445, of 1.5 to 8 mm.sup.2/s and selected from polyalphaolefins; and at least one thickening polymer.

This disclosure relates to grease compositions having at least one base oil, and at least one polyurea thickener. The at least one polyurea thickener is prepared by reacting an isocyanate-terminated prepolymer with at least one amine under reaction conditions sufficient to prepare the at least one polyurea thickener. The isocyanate-terminated prepolymer is prepared by reacting a polyisocyanate with a polyol, at an NCO/OH equivalent ratio of 1.05:1 to 10:1, under reaction conditions sufficient to prepare said isocyanate-terminated prepolymer. When the grease compositions are used under high temperature conditions, structural stability and resistance to breaking down in accordance with DIN 51821 (FAG FE9) is improved. This disclosure also relates to a method of preparing the grease compositions. This disclosure further relates to a method for improving high temperature performance of a grease composition in a mechanical component lubricated with the grease composition.