This study delves into the impact of an air dam on the aerodynamics of trucks and its consequential effect on the vehicle's fuel economy. Initially, the vehicle exhibited a coefficient of drag at 0.98, representing its aerodynamic efficiency and airflow resistance. Post-application of aerodynamic enhancements, specifically the integration of an air dam, a notable reduction in the coefficient of drag to 0.697 was achieved. This reduction signifies a substantial improvement in the vehicle's aerodynamic performance, indicating a pronounced decrease in air resistance. This paper also focuses on the effect of air dam on fuel consumption. For assessing that, three cases have been taken into account: 40, 60, and 80 km/hr. The findings underscore the significance of air dam implementation in augmenting truck aerodynamics, potentially leading to enhanced fuel efficiency of 28.881% improvement.