Always full water, pantry, and fridge when we leave and replace used items as they are used except for the last about 2 days before getting back home. Same with all our RV's over the years as it's not the load that determines fuel mileage but the speed driven and why? Rolling resistance is the same no mater the speed driven but wind resistance multiplies as speed drive increases and thus requires more fuel the be used.
Why always full up on all water and food etc when leaving? Never know what can or will happen along the way and we like always being totally prepared for about anything even a change of mind when on the way for our final destination as we virtually never make reservations and are very flexible. Only going to go to or stay at a CG or location for a short time, not buying it! Being very flexible leads you to find new, more, and often even better places being explored and learned. Not just the same o -same o boring stick in the mud zombies!
Never once in over 52 years have we not been able to find a CG close to our route with an open site yet with having NO reservations anywhere in the USA or Canada. So simple to call ahead today on a cell that works all over the country like Verizon if you take along CG books like a: Woodall's/Good Sam, PPA, COE directory, etc or even the Mile Post when going to Alaska.
Even sometimes we will stay at a Cracker Barrel or other etc (not a Walmart parking lot for us) when just wanting to eat a good quick meal out and sleep overnight and be on our way. That's why RV's are self-contained and besides a good meal after driving all day whether made in your RV or a restaurant is a real plus and a step up from just a McDonalds, Burger King, Wendy's, ETC!
Yup, up in the morning and your hot shower awaits you just a few feet away and you don't even have to go outside your very own traveling home. Making the journey fun is a big part of a trip's real enjoyment. Besides, when you get to your destination, stay a short time as/if planned, you'll just be heading back home anyway! Rubs us raw paying $30+ just to sleep over night at a CG and why we sure do use our PPA (many years now and it pays for a whole years membership with 2-3 night stays. Never will or have been a leech and will always patronized a place that doesn't charge for an overnight RV stay as we should and do! We want them and they need us as it's a 2 way street!!!
You are NOT buying the CG or the campsite and just renting it for the time being on it and what do you really have when you leave? A paper receipt for your monies paid! Then, that same site gets new users probably hours later and they will leave with a receipt just like you have!