Active grille shutter (AGS) in a vehicle provides aerodynamic benefit at high vehicle speed by closing the front-end grille opening. At the same time, this causes lesser air to flow through the cooling module which includes the condenser. This results in a higher head pressure (AC compressor discharge pressure of the refrigerant). Higher head pressure causes the compressor to work more thereby possibly negating the aerodynamic benefits. This thesis shows a model-based method to quantify the fuel consumption in different scenarios to justify the AGS position (fully open or fully closed) to have better fuel economy. The impact of AGS is more felt at highway speed, so the AGS will be open at low speed or idle.