This disclosure provides a thermal management system and method that can recommend operational behavior to an operator of an engine system to optimize fuel economy over a period of time in which a components of the engine system is in a warm up and/or regeneration state. In one representative embodiment, the expected temperature change of the engine component at a later time is determined based on inefficient operation of the engine, such as a transmission down shift resulting in higher engine speed and lower engine torque, and the expected temperature change of the engine component resulting from operating the engine under current conditions or expected conditions at that later time is determined. A determination is made as to whether the inefficient engine operation is the optimal operation in view of fuel economy and a recommendation is generated for the operator based if optimal operation is determined.