(GTWR) Gross Trailer Weight Rating
(GTWR) Gross Trailer Weight Rating:
In motor vehicles, the gross trailer weight rating (GTWR) is the total mass of a road trailer that is loaded to capacity, including the weight of the trailer itself, plus fluids, and cargo, that a vehicle is rated to tow by the manufacturer. In the United States and Canada, the static tongue load, the weight of the trailer as measured at the trailer coupling, is generally recommended to be 10-15% of the GTWR.
In the United States and Canada, there are four main weight classes of trailer hitches as defined by the Society of Automotive Engineers(SAE):
Class I — rated to 2,000 pounds (907 kg)
Class II — rated to 3,500 pounds (1,588 kg)
Class III — rated to 5,000 pounds (2,268 kg)
Class IV — rated to 10,000 pounds (4,536 kg)