Towing a trailer may seem like a simple process. You hitch your trailer to your vehicle, load your cargo, and hit the road, right? Not quite. In order to tow a trailer safely, you must know how to properly hitch it as well as the best way to load your trailer, how to maintain safety on the road, and more. One major factor that will help you stay safe while hauling a trailer is knowing your trailer tow limit.
One major factor in learning your trailer’s towing limit is knowing your vehicle’s towing capacity. The towing capacity for your vehicle as it relates to maximum Gross Trailer Weight (GTW) and maximum Gross Combined Weight Rating (GCWR). Both GTW and GCWR can be found in the Owner’s Manual of your tow vehicle. Exceeding the maximum towing capacity of your tow vehicle can put additional strain on your tow vehicle’s engine, as well as drive-train, which can increase the chance of serious maintenance problems for your tow vehicle as well as air pressure issues with your trailer’s tires. A trailer that weighs too much for the tow vehicle can also create stability problems, which can lead to serious injury or death.
In addition to your vehicle’s towing capacity, you need to know and understand how much your trailer weighs, as well as its payload capacity, tongue weight, Gross Vehicle Weight Rating (GVWR), and Gross Axle Weight Rating (GAWR). Understanding the definitions of the following terms will help you determine your trailer’s tow limit.
- Gross Axle Weight Rating (GAWR) is the most distributed weight the axle of a vehicle can support. Typically, the GAWR will include FR to indicate front axles or RR to indicate rear axles.
- Gross Vehicle Weight Rating (GVWR) is the most weight allowed of both your trailer and cargo. The GAWR will be posted on your trailer’s VIN label. The VIN label can be found on the driver’s side of our newer trailers and on the tongue of older trailers.
- Trailer weight is the empty weight of your fully assembled trailer. This can be checked by weighing your empty trailer at a truck stop or another location with a certified scale.
- Payload capacity refers to the total weight capacity of your trailer. You can calculate maximum payload capacity by subtracting the trailer weight from the GVWR.
- Tongue weight is the amount of your trailer’s weight that transfers to your tow vehicle through the trailer’s tongue or gooseneck. Tongue weight can be measured on any certified scale. First, drive your tow vehicle onto the scale and measure its weight. Its weight needs to be less than the GVWR. Next, pull your trailer onto the scale and uncouple it from your tow vehicle. Leave it on the scale and get a ticket that lists the total trailer weight. After that, reconnect and drive your tow vehicle’s wheels off the scale so only your trailer’s axles are on the scale and get a ticket with the trailer’s axle weight measurement. Subtract the axle weight from the total trailer weight to determine your trailer’s hitch weight. A general rule of thumb is that 20 to 25% of the total weight of a trailer plus its cargo should be placed on the tongue of the trailer.
Determining Your Trailer’s Load Limit
Once you understand these factors, you can start working toward determining the safest load limit for your trailer. First, locate the Federal Certification / VIN label on the front half of your trailer. It should be located on the left side. This label will show you your trailer’s GVWR and GWAR. Trailers with a GVWR of 10,000 pounds or less will have a vehicle placard located in the same spot as the VIN label. The placard will provide tire and loading information, as well as a note regarding the maximum cargo capacity. Cargo can be added to your trailer up to the maximum weight specified on the placard. Remember, the total weight of your fully loaded trailer can’t exceed the listed GVWR. Be sure to load your trailer properly and follow the proper air pressure recommendations listed on your trailer’s VIN label or Tire Placard.
The best way to know the actual weight of your trailer is to use a public scale. Your dealer is your best resource for learning the best methods to follow for determining the weights related to your trailer, including weight empty or unloaded, weights per axle, hitch or king-pin, and total weight.
For trailers over 10,000 pounds GVWR, first determine the empty weight of your trailer. Then, find the GVWR on the VIN label. Subtract the empty weight of your trailer from the GVWR listed. The resulting number will be the maximum available cargo capacity of the trailer. Do not exceed this number.
Determining Your Tow Vehicle’s Load Limit
In addition to knowing your trailer’s towing limit, you need to know how to determine the correct load limit for your tow vehicle. This is especially important if you plan to tow with different vehicles. First, look at your vehicle’s placard for a statement that reads “The combined weight of occupants and cargo should never exceed XXX lbs.” Then, determine the weight of the driver and any passengers that will be riding while you tow. Subtract the combined weight of the driver and passengers from the number listed on the placard. The resulting number is your available amount of cargo and luggage capacity. For example, if the total weight of your passengers is 750 pounds and the number listed on your trailer’s placard is 1400 pounds, your available cargo and luggage capacity is 650 pounds.
Next, determine the combined weight of luggage and cargo you’re loading on the vehicle. That weight shouldn’t exceed the available cargo and luggage capacity you just calculated. Then, you’ll want to see how much weight will be transferred from your trailer to your tow vehicle. Your tow vehicle’s manual will help you determine how the available cargo and luggage capacity of the vehicle is affected by weight transfer from the trailer.
Determining your trailer’s tow limit is an important process to ensure safety while towing. Always check with your owner’s manual or consult with your dealer for questions specific to your trailer.