I travel up and down the east coast. My water tank is in the front compartment. I always leave with it full, My gas mileage doesn't change, and if it did it wouldn't be that much. Whats the difference if your towing 6k or 6.5K. It was designed for it. I stay at walmart, cracker barrel. Take shower when I get up and hit the road, you have your own bathroom to use. Makes life a lot easier. Thats why I bought it.
2009 Ford F250 Super Duty
2008 Flagstaff Ultralite 23FBS with slide out (standard)
2006 H-D Flhxi
2001 H-D Dyna
Champion gen 4000