An apparatus for reducing aerodynamic resistance in an over the road vehicle is provided. The apparatus can include a frame assembly and first and second airfoils to be coupled to the vehicle by the frame assembly ahead of first and second tires of an axle assembly provided to the vehicle. The first and second airfoils each include an air deflecting surface with a convex outward portion that extends away from a leading edge that is to be directed into the airflow to transition the portions of the airflow directed toward the first and second tires outward beyond the externally exposed sides of the first and second tires. The first and second airfoils are also spaced laterally apart from each other when coupled to the vehicle by the frame assembly to define an aperture between the first and second airfoils through which at least a portion of the airflow directed toward the axle assembly is to pass while the vehicle is underway.