A method for controlling a hybrid vehicle having an engine includes automatically stopping the engine in response to vehicle power demand dropping below currently available electrical power, and automatically starting the engine when vehicle power demand is at a first offset below currently available electrical power to reduce a time delay for starting the engine and increase a currently available vehicle power to move the vehicle up a grade in response to receiving a signal indicating a positive grade. A hybrid vehicle includes an engine, an electric machine, and a controller. The controller is configured to control starting/stopping of the engine in response to a first driver demand when receiving a signal indicative of a road grade angle exceeding a corresponding threshold and in response to a second driver demand otherwise.