A vehicle is provided with a controller that implements a method of controlling oil delivery to the vehicle. The method includes increasing at least one of rate of flow of oil and pressure of oil flowing from an oil pump to a motor/generator or to a gearing arrangement that is operatively connected to the vehicle wheels, thereby increasing resistance to rotation of a rotor of the motor/generator or of the gearing arrangement and slowing the vehicle wheels as well as increasing the oil temperature to reduce friction losses. The controlled oil delivery is in response to a vehicle operating condition such as a condition indicative of a desired decrease in torque at the vehicle wheels or oil temperature below a predetermined temperature.