[aerohead]

I believe CAR and DRIVER quantified an improvement for their "Crisis Fighter Pinto",back in March of '74.So many Big-Dogs have mentioned or recommended the practice over the decades,that I've always considered it an integral part of any streamlining project.Sorry!,I have no specific quantitative data for the solitary modification.If you'll look around,many new cars have fake grille openings.It gives the stylists busywork,and streamlines the car without the owner's awareness.