One of the most important aspects in towing a trailer is knowing all of your weights, limits and capacities. Having a firm knowledge of these different weights will help you stay safe on the road and not add stress to your towing vehicle. Let’s review one of the most important figures, the gross trailer weight, including how to calculate it. Having an optimum gross trailer weight will allow you to have a safe and pleasant trip.


 

What is Gross Trailer Weight?

Many rookie RVers use the term gross towing weight which is not entirely incorrect but a bit misleading. The proper term in the industry is gross trailer weight (GTW.) It is critical that you know your correct GTW to make sure you are within your vehicles towing capacity, your tongue weight is optimal and that you are using the correct class of hitch. Failure to stay within the proper limits of these weights can lead to added stress on the towing vehicle, the trailer itself, dangerous trailer sway and other problems. So what is GTW?

The GTW of a trailer is the entire weight of the trailer fully loaded. This includes the weight of the trailer itself including full fuel and waste tanks in addition to any cargo, or passengers, that the trailer is carrying. GTW is not to be confused with curb weight or dry weight. Curb weight is the gross weight of the trailer including full fuel and waste tanks but not including any additional personal cargo or optional equipment.

Dry weight refers to the trailer’s weight as it comes off the assembly line, lacking full tanks or additional equipment. When it comes to GTW, you want to include everything. 

How Do You Find Your GTW?

Luckily for RVers, finding their GTW is a relatively simple process. Use the Internet or phone book to locate a weigh station near you or on your planned route. This can include truck weigh stations, public scales, or even local supply companies that need to weigh their delivery vehicles often. Simply drive your trailer onto the scales, detach it from your vehicle, make sure the towing vehicle is completely off the scales and take your measurement. It is best to take this measurement with full fuel tanks, water and waste tanks and with all cargo in board, you want to know the weight of everything you will possibly be carrying. 

If you cannot locate scales or need a very fast measurement you can do a calculation of the trailer’s curb weight, located in the trailer’s operator’s manual, plus the weight of your cargo. Most of this time this weight will be inaccurate compared the correct GTW so I only recommend it using it for ballpark figures.

Why is Your GTW So Important?

Your GTW is one of the fundamental keys to making sure your towing system is safe and reliable. Limits aren’t printed for weight capacities just to fill space, they are carefully calculated and honed during the vehicle and trailer’s test period to be optimal for the entire system. Going over these limits can destabilize both the trailer and tow vehicle potentially leading to damaged or broken axles, hitches, frames and the engine of the tow vehicle itself. Not to mention overloaded trailers are a leading cause of accidents in the RV world. 

So get to know your trailer and its weight, the whole gross of it, for a happy and healthy towing system and a relaxed driver.