I have both CV's removed, and the front driveshaft removed, and do not see any real improvement in the MPG.

I have not yet replaced my CV's that I blew while mudding, and just took the front driveshaft off because it was not doing much good anyway and the CV joints on it (yes our front driveshafts have CV on them, U-joints on the rear driveshaft) were completely shot from just being old, so I already have new ones, but am waiting for a real good reason to replace it all.