Trailer Cargo Capacities and Load Distribution

Every trailer has a designed maximum weight capacity. This maximum weight capacity is stated on the trailer and in the trailer manuals as the gross vehicle weight rating or GVWR. The GVWR is printed on a label or placard, often referred to as the certification or VIN label, which is mounted on the left front side of the trailer, typically within 6 inches of the floor line, or near the coupler. In practical terms, the GVWR is the most a trailer should ever weigh with all cargo loaded. Exceeding this capacity rating overloads the trailer and can lead to safety problems, including poor handling and control, reduced braking ability, increased stopping distances and premature wearing of suspension system components, including tires and brakes.

If you ever have a question about how much your fully loaded trailer weighs, you should take it to vehicle scales and weigh it. Truck service areas, grain elevators, and weigh stations are just a few of the locations where such scales can be found. If the amount of cargo causes the trailer to exceed its GVWR, you should unload some of the cargo items to reduce the weight below the GVWR.

Other weight capacities of the trailer are also provided on the certification label. The most weight an axle can bear is the gross axle weight rating or GAWR. If the trailer has more than one axle, each axle will have weight rating information provided on the certification label.

The distribution of cargo loaded evenly within the trailer, both side-to-side and front-to-back, is important to travel safety. For example, if a trailer weighs 5000 pounds empty and has a GVWR of 10,000 pounds, 5000 pounds of cargo can be added to the trailer. However, if all 5000 pounds were to be added to the right side of the trailer, the trailer would not handle correctly and the tire weight ratings on the right side would likely be exceeded. Likewise, if the 5000 pounds were added only to the front of the trailer or only to the rear, handling problems such as swaying would likely occur. Either of these conditions could cause an accident. The heaviest items should be placed near the floor and directly over or as close to the forward-most axles as practicable. For the best information on trailer and tow vehicle handling characteristics, consult your trailer manufacturer’s owner’s manual regarding cargo loading recommendations.

TSIC
The Trailer Safety Industry Coalition is a coalition of trailer and component manufacturers formed to identify and address issues that can improve the safety of towable equipment. The TSIC is developing a series of safety tips to assist consumers in maintaining their towable equipment. This is the third in a series of Safety Tips.

You can learn more about TSIC’s efforts, and recommended practices at www.natm.com, www.rvia.org, www.nmma.org, and www.ntea.com. Feel free to contact us so that we may continue this dialogue. The National Highway Traffic Safety Administration (NHTSA) also publishes brochures providing guidelines for safely towing trailers such as “Towing a Trailer” and “Safety Tips for Driving with a Trailer.” These and other publications are available at the www.nhtsa.dot.gov website.