An electric motor driveline fluid for an electric motor system including a lubricating base oil, at least one sulfurized component, and at least one dispersant derived from a polyisobutylene having an average number molecular weight of at least 2000. The electric motor driveline fluid provides acceptable wear performance as well as good electrical conductivity and oxidative stability for use in electric motor system fluids having a low viscosity when select elemental relationships of phosphorus, sulfur, and calcium and included in the fluid.