A few things come into play here. The hitch rating and the GCWR (Gross Combined Weight Rating) My unit has a 10K rated hitch that can tow up to 10K. However, my unit has a maximum GCWR of 30,000# which means that I need to deduct the loaded weight of my unit from what I can tow. For example if I am loaded to 25,000# then I can safely tow 5,000# however if I am loaded to 21,000# I can tow 9,000#. It is very rare unit that has a GCWR that allows you to tow the full hitch rating while at your GVWR (Gross Vehicle Weight Rating). There are a few but not many. As long as you understand the limitations and stay under the weights there won't be any problems.