[aerohead]

Originally Posted by IsaacMTSU

Having the wheels slightly inside the wheel well would be better than having them sticking out and I would think slightly inside would also be a little better than having them more flush like the Corolla wheels. I've read that 25% of a car's total drag is caused by the wheels alone... although, if you add up all the crap stats I've read you'd have a number way over 100%
I can't find a good photo example of the turbulence caused by the face of a spinning wheel, but here is a bike wheel...

On a car, the pocket of turbulence on the face (where the yellow specs are) would be much thicker and stick out further away from the face.

WARNING: Terrible MS Paint Drawings Below

Flush Fit


Inside Fit


Those are not exact science, just the best I can do on my laptop without COSMOS FloWorks. If it were my car, I'd say leave them tucked in there, especially since you lowered the car already and that helps git rid of the wheel well drag more than anything.

I believe that rotating tire drag is Cd 0.005.It would depend on the wheel/cover/combination.