heat transfer to power input dq dp one example of a liquid to air heat exchanger to which the present disclosure applies is commonly called a radiator although the predominant heat transfer mode associated with the radiator is actually convection it is commonly referred to as a radiator for convenience and simplicity the liquid to air heat exchanger is referred to as a radiator in the following description in fig1 a vehicle 10 having four wheels 12 an internal combustion engine 14 and a radiator 16 for providing cooling for engine 14 is shown a liquid coolant typically a mixture of water and ethylene glycol is provided to a water jacket cast in engine 14 by a pump 18 typically pump 18 is driven by engine 14 however in some applications pump 18 is either electrically driven driven by a variable speed clutch hydraulically driven or driven by some other actively controllable means so that pump 18 can be operated partially or fully independently of engine rotational speed a fan 20 which is either electrically driven driven by a variable speed clutch hydraulically driven or driven by some other actively controllable means is provided proximate radiator 16 air is forced across radiator 16 due to vehicle speed and or fan 20 an electronic control unit ecu 30 is coupled to a variety of sensors and actuators which may include.