Systems and methods are disclosed for improving the aerodynamic efficiency (e.g., reduce drag) on vehicles, such as class 8 tractors. In some disclosed examples, the systems and methods utilize exhausted gases from an internal combustion engine of the vehicle to direct a stream of gas forwardly of the vehicle. In other disclosed examples, the systems and methods utilize generated air flow from, for example, electric fans, engine driven or pneumatically/hydraulically driven pumps, etc., to direct a stream of gas forwardly of the vehicle for reducing the aerodynamic drag on vehicles. In yet other disclosed examples, the systems and methods utilize a unique configuration of the vehicle's radiator fan(s) in order to direct a stream of gas forwardly of the vehicle.