A high efficiency vehicle propulsion system to propel a vehicle using a hydraulic motor pump functioning as motor connected to the vehicle wheels. Vehicle braking and deceleration energy is recaptured using the same hydraulic motor pump functioning as a pump and stored in an inertia wheel configured as a gyroscope. Energy is stored in and retrieved from the inertia wheel by the use of a hydraulic motor pump functioning as a motor to store energy in the inertia wheel of the gyroscope or as a pump or to retrieve energy from the inertial wheel of the gyroscope. Energy to serve the system is derived from the use of a small engine running infrequently and intermittently. Additional energy is retrieved by the use of an active shock absorption system. Energy management and vehicle propulsion are controlled by a central computer processing signals derived from action of an on-board operator, an on-board program of from a remote source. Vehicle roll over accidents are inhibited by the use of the inertial stability of the gyroscope to prevent excessive vehicle roll attitude.