I installed air tabs on my Holiday Rambler 33' Vacationer and became a believer. The biggest improvement I noticed was fast passing semi's did not cause the coach to sway as before. That doesn't mean some semi's still cause swaying but it eliminated the major of the problems. I believe fuel consumption may have improved. I normally pulled a vehicle but the one time I did a round trip to Ca. with out the car, fuel consumption was the best I ever experienced with or without an auto behind.