[Xringer]

If your rims are acting as air pumps, moving air out (or in) the side of the wheel,
then putting a wheel skirt over the wheel, may be like holding a solid plate 1/2" in front of your desk fan. The work load on the motor is going to increase.

But, if you had a Moon discs installed on your car? Would the the air pump even be able to start? Since the moon disc is spinning with the wheel, (and not fixed relative to the wheel, like the skirt) the air under the disc shouldn't be moving much and not be a factor at all.

Yeah, it sounds real logical that a skirt should be used with discs.

Did those Gassavers guys that had poor skirt performance have moon discs installed?