Nope. You just declare a weight. If you're underweight no big deal...you're just paying extra wheelage tax. If you're overweight you can get slapped with a pretty hefty fine, but RV's are not subject to weighing up at the stations so I don't know how you would get plucked. My bus teeters dangerous close to it's limit (like within 500 lbs with just me and a full tank of fuel
). Every year I tell myself I'm going to jump a class, but then I never do. Honestly, by the time we load up 5-6 people, their stuff, food, water, coolers in addition to the fridge, firewood, instruments, extra fuel, the gennie, etc I think I might be best served by jumping two weight classes (3000 lbs per class), but damn if that doesn't sting in the pocketbook.