The first step in selecting the proper hitch for your vehicle is to know your own vehicle's capacities. Along with being able to tell your professional hitch installer the make and model of your car, you must know the vehicle's maximum towing capacity. This is listed in the vehicle owner's manual. These are two of the most important items to consider when towing. The GTW is the weight of the fully loaded trailer in its actual towing condition.
Tongue weight is the downward force exerted on the hitch ball by the trailer coupler.
A trailer scale or other measuring device should be used to determine the actual tongue weight. Next you must match the trailer and tow vehicle to find the right hitch. The vehicle needs to be capable of towing the intended weight. Consumers are warned not to exceed the upper limits of the weights listed in the owner's manual. For heavier loads consider a hitch with a higher weight rating, a weight distributing hitch, and possibly a trailer with dual axles.