I always fill up with water regardless of where we're heading. I know, I know, I'm carrying extra weight with the water but I feel that if a little less gas milage results, no big deal! I do not like running out of water on the road or fussing around trying to find water when we arrive at our destination, it's a real irritant.
Days camping (2015)----88 days
Days camping (2016) ---110 days
2016 Wildcat MAXX 28RKX (33' TT), 2007 13' Scamp
2015 Ram Laramie Hemi
30 years RV'ing
12 different RV's