Abstract: An aerodynamic wing apparatus for mounting on a top panel portion of a vehicle such as a car, a truck cargo box or trailer portion of a tractor-trailer vehicle, in order to improve the aerodynamic movement of the vehicle through the air, provide lift to the vehicle in order to reduce the effective weight thereof, improve fuel economy of the vehicle, and reduce carbon emissions. The wing apparatus includes a main wing body having an airfoil-shaped cross-section, with a rounded leading edge and a substantially sharp trailing edge. The main wing body is adjustably movable to account for changing ambient conditions. The wing apparatus also includes a support frame for mounting the main wing body to a vehicle so as to be spaced away from a top panel portion thereof. A control system may also be provided to control operation of the apparatus, and a method of operation is described.