Towing hitch categories or classes relate to the total gross weight the hitch is approved to carry. The class also relates to tongue weight of the hitch. Trailer hitches come in classes I through V.
A class II hitch was designed to work with midsize trucks, sport utility vehicles and cars. It has a gross trailer weight rating of 3,500 pounds. The tongue weight rating of a class II hitch is 350 pounds. A class II hitch is appropriate for towing a small boat or pop-up trailer.
A hitch needs to be rated high enough to tow the weight of the trailer, but it should not exceed the towing capacity of the car or truck pulling the trailer. The vehicle's owner's manual should tell you the maximum tow capacity.
Tongue weight refers to the maximum downward force the hitch can handle. It is important that this weight is not exceeded as it can lead to dangerous conditions, such as trailer sway. A properly loaded trailer will have 60 percent of its weight in front of the trailer axles.
