NOVELTY - Providing a hybrid vehicle system which has an internal combustion engine and another machine which may provide motive force to the wheels in such a manner to satisfy or attend to demands of engine dependent auxiliary devices to better provide secondary functions such as emission control etc..    USE - As a vehicle system.    ADVANTAGE - The invention provides that by operating the engine at its most efficient operating condition while providing a secondary function, e.g. cabin cooling, the fuel penalty exacted by providing that secondary function is minimized. It provides that torque fluctuations of the engine to provide transitions, for the purpose of a secondary device, may be made without affecting torque at the driving wheels. Further, the transitions may take place in a more fuel-efficient manner than provided in prior art. The secondary function can be provided upon demand rather than having to postpone providing the function or inadequately providing the function. The invention may be possible to attend to two secondary devices simultaneously.    DETAILED DESCRIPTION - A vehicle system comprises at least two machines capable of being coupled to driving wheels (32) of a vehicle, where one of the machine is an internal combustion engine; engine dependent auxiliary device(s) coupled to the engine; and an engine controller operably connected to the machines to determine when the engine dependent auxiliary device should be attended to and to determine whether a current engine operating condition is within an acceptable engine operating range which satisfies the engine dependent auxiliary device.    INDEPENDENT CLAIMS are also included for:    (a) a method of controlling the vehicle system having a primary machine which is an internal combustion engine and secondary machine(s), comprising determining that the engine dependent auxiliary device should be attended to; determining a desired engine operating condition that satisfies the engine dependent auxiliary device; and commanding the engine to attain the desired engine operating condition; and    (b) a computer readable storage medium having stored data representing instructions executable by a computer to control the vehicle system, comprising instructions for determining whether the engine dependent auxiliary device should be attended to; and instructions for determining whether the current engine operating condition is within the acceptable engine operating range which satisfies the engine dependent auxiliary device.    DESCRIPTION OF DRAWING(S) - The figure is a schematic representation of a hybrid vehicle configuration showing ancillary components which may provide secondary functions onboard the vehicle.    Intake manifold (12)    Driving wheels (32)    Injector (52)    Engine (10)    Electric motor (28)    Driving wheels (32)    Power split device (20)    Engine output shaft (34)    Output shaft (36)    Generator (22)    Battery (26)    Inverter (24)    Throttle valve (48)    Exhaust manifold (14)    Aftertreatment device (16)