A vehicle controlling system includes an engine serving as a power source of a vehicle; an electric storage device; an assist device that assists an operation of a driver by consuming power from the electric storage device so as to operate a running device that changes the running condition of the vehicle; and a starting device that consumes power from the electric storage device so as to start the engine, wherein the starting device automatically starts the engine based upon a physical quantity concerning the engine, and the start of the engine is inhibited while the assist device operates the running device, when the execution of an inertial running in which the engine is stopped to allow the vehicle to run with inertia.