I have a 2014 Grey Wolf 26DBH and all specs I can find for tank sizes list the fresh water at 50 gal, gray at 41 gal and black at 31 gal. However, my experience is otherwise. With the unit leveled, I can't put more than 40 gal into an empty fresh water tank, it starts coming out the overflow. The black tank is completely full with water coming up the stool at 21 gal. I've never measured the gray tank.
2014 Forest River Grey Wolf 26DBH Trailer : Reviews, Prices and Specs : RV Guide
Grey Wolf Travel Trailer by Forest River
So, are the specs wrong or do I have a problem to worry about?