I think the most limiting factor for determining capacity is the GVWR - actual total weight of the vehicle including the passengers, fuel, other cargo and the pin weight of the trailer. I have a '04 Ram 3500, but with a GVWR of only 9,900 lbs, I was slightly over my GVWR at its heaviest weigh - in. The truck weight w/o trailer was 8,100 lbs (driver, 2 pax, dog, firewood, dutch ovens, extra beverages, etc.) + pin of 1,980 = 10,080, or 180 lbs over. In hindsight, I could have moved some of the load from the truck to the trailer, and left the daughter at home ;). As stated, that was my heaviest load, so I feel comfortable that I'm closer to the 9,900 GVWR on most typical trips. At least having weighed the set up has allowed me to better judge what and where I'm loading up with. Just my $0.02 worth - I know newer vehicles have higher GVWR ratings.