The present disclosure provides an airstream deflector fairing comprising a front or fore end having a leading edge attached to an undercarriage of a wheeled vehicle. The fairing further includes a rear or aft end and a lower bottom portion of the fairing includes a panel facing the ground at an angle which in turn directs an airstream passing thereunder downwardly and outwardly relative to the undercarriage and substantially at an area below a trailing axle downstream from the fairing. The lower bottom panel includes an angle of declination relative to the undercarriage from about 12 degrees to about 24 degrees.
