Brad-
If there is any pickup in fuel mileage with removal of the mudflap, it likely pales in comparison to the resulting toad repair costs. The mudflap doesn't completely protect your toad, but certainly helps. Rocks bounce at speed, and passing vehicles can shower your toad (and coach) from the side; the proof is in the chips in my coach's front cap, and the replacement of both coach and toad windshields, after a long trip over a gravelled winter highway shared with sugar beet trucks in a hurry.
Our mudflap gets beat up too, probably more than most. Shorter rigs like yours and mine have short driveshafts. That means the coach can't be allowed to raise as high in the back as 40+ footers, or there is risk of damage to the drive system from the shaft's steep angle while turning. The coach manufacturer therefore installs limiting straps to keep the back end down; our coach at full lift moves up 4 inches in the front but only 2 inches in the back, for example. The consequence of this is that at full lift, everything at the very back bottom of the rig may be actually levered lower at full lift than in travel mode. So when you lift the coach to clear some rise or object on the ground, or more often a dipped driveway entrance, the mudflap can get caught between the ground and the hitch, scratching and/or bending it. I've learned to guess when I've lifted about 2 inches, and try to hold it there.
Dumping air at a campsite or to get under something overhead can trap the flap underneath also, if there is a slight ground rise under it. The flap's hang chain's mounts have done their share of damage to our flap as a result. Nevertheless, to answer your question, I wouldn't remove my mudflap, as I believe it intercepts its share of bouncing undercarriage gravel, and I've managed to repair it with less hassle and expense than the toad. I added a Roadmaster guard to the toad's towbar mount as additional protection, and new dings to the front of the toad stopped.
-Joel
