Patent ID: 7237634

Claim:
A hybrid vehicle, comprising: one or more wheels; an internal combustion engine operable to propel the hybrid vehicle by providing torque to the one or more wheels; a first electric motor coupled to the engine; a second electric motor operable to propel the hybrid vehicle by providing torque to the one or more wheels; a battery coupled to the first and second electric motors, operable to: provide current to the first and/or the second electric motors; and accept current from the first and second electric motors; and a controller, operable to control the flow of electrical and mechanical power between the engine, the first and the second electric motors, and the one or more wheels; wherein the controller is operable to operate the engine when torque required from the engine to propel the hybrid vehicle and/or to drive one or more of the first or the second motors to charge the battery is at least equal to a setpoint (SP) above which the torque produced by the engine is efficiently produced, and wherein the torque produced by the engine when operated at the SP is substantially less than the maximum torque output (MTO) of the engine.