[lunarhighway]

It's an interesting thought, but as always i think it depends. although lowering is usually seen as a way to improve aerodynamics, i've seen a few indications that sometimes a raised floor will improve aero. for cars like the exclusive bristol fighter it's mentioned it has a high ground clearance for better airflow, and the promissing but sadly vaporised loremo concept also had a relative high ground clearance, creating some sort of tunnel between the thin faired wheels, even the suspention was set up so the center floor could be flat from the front the the back.

all else being equal i think raising the entire floopan can improve airflow underneath and cut down drag, especially when the underbody is flat. however this is on a new design, where raising the floorpan, but leaving everything else in place means less frontal area, if you raise the entire car, wich is pretty much the only option on an existing car, you'll generate more frontal area.

if you know your stock drag coeficient(Cd), and you measure your actual frontal area(A...the surface of a front projection of the car) you could get your actual CdA. now you could make a new frontal projection of how the car would look raised and get a fictional CdA that assumes your Cd stays the same. from this you could calculate how much the Cd would have to drop to a: break even, and b: make an improvement.

from what i've seen on the mercedes website that lists the drag coeficient for every version of a model they make it seems that more high powered versions with wider tires have Cd's that are sometimes 0.03-0.04 higher, that the slipperiest models (most likely the cause of more grill opening and wider tires0).

so this sugest that wider tires not only increase frontal area but also drag coeficient.

tire fairings and smoothing out the underside are always a good thing especially if the vehicle must be raised form practical reasons, however, i don't think raising an existing vehicle can give much improvement.