Interaction between a vehicles powertrain and the ancillaries required to provide an effective HVAC system can have a significant impact on vehicle efficiency, both due to parasitic drive losses and thermal effects. This is becoming increasingly prominent with technologies such as start/stop, variable coolant pumps and switchable oil circuits, all of which must be managed to ensure the comfort of the occupants without being detrimental to vehicle performance. At Powertrain Technology we have a range of experience with these technologies, including: