When shopping for your new RV, one of the most important questions you can ask yourself is whether or not your vehicle can tow the rig you’re interested in. There are serious risks to exceeding the maximum towing capacity of your vehicle. Your brakes can start to wear, you’ll shorten the life span of your tires, and you could also sustain costly damage to your transmission. But more devastating than any of these mechanical consequences is the risk you pose to yourself, your passengers, and the other vehicles on the roadway, because towing more than your vehicle can handle puts you at a higher risk of losing control of your rig. So stay safe as you travel from point A to point B by following this easy-to-understand guide for towing capacity.
Learning the Lingo
Payload Capacity: How much cargo and passenger weight your tow vehicle is capable of carrying
Towing Capacity: How much trailer weight your tow vehicle can safely haul
Gross Hitch Weight Rating (GHWR): The maximum recommended weight of the RV’s load that can press down on your tow vehicle and be supported by the rear axle
Maximum Tongue Weight: The maximum recommended weight that can press down on your tow vehicle’s hitch ball (applicable to travel trailers, typically 15% of the GTW)
Maximum King Pin Weight: The maximum recommended weight that can press down on your king pin and truck bed (applicable to fifth wheels, typically 25% of the GTW)
Gross Axle Weight Rating (GAWR): The maximum recommended weight that a single axle can support. This number will be noted on the driver side door jamb sticker for both front and rear axles.
Gross Axle Weight (GAW): The actual weight each axle is supporting. Local public scales and weigh systems can be useful for calculating this number.
Dry Weight: The actual weight of your vehicle or RV without any added cargo or passengers
Gross Vehicle Weight Rating (GVWR): The maximum recommended weight of your fully-loaded tow vehicle. This number will be noted on the driver side door jamb sticker.
Gross Vehicle Weight (GVW): The actual weight of your vehicle, including all cargo, passengers, and fuel. Local public scales and weigh systems can be useful for calculating this number.
Gross Trailer Weight Rating (GTWR): The maximum recommended weight of your fully-loaded RV. This number will be noted on your RV, or you can check with your dealership.
Gross Trailer Weight (GTW): The actual weight of your RV with all the cargo loaded. Local public scales and weigh systems can be useful for calculating this number.
Gross Combined Weight (GCW): The actual weight of the tow vehicle and RV combined when fully-loaded. Local public scales and weigh systems can be useful for calculating this number.
Gross Combined Weight Rating (GCWR): The maximum allowable combined weight of your vehicle and RV added together when fully-loaded. This number can typically be found in your owner’s manual.
Towing Capacity: The maximum allowable weight that a vehicle can tow. This number can typically be found in the owner’s manual.
Running the Numbers
To figure out what your vehicle can tow, you’ll need to do some math. So grab a calculator or the nearest brainiac and let’s crunch some numbers! Here are the equations:
Calculating Gross Vehicle Weight
Dry Weight + Cargo Weight + Passenger Weight = GVW
*Your GVWR must always be higher than your GVW
Calculating Gross Combined Weight
GVW + GTW = GCW
*Your GCWR must always be higher than your GCW
Calculating Maximum Hitch Weight
GTW x .25 = Maximum King Pin Weight (fifth wheels)
GTW x .15 = Maximum Tongue Weight (travel trailers)
*Make sure you evenly distribute the weight of your cargo throughout your trailer so that you can have an accurate estimate of what your hitch weight will be
Calculating Rear Gross Axle Weight
Visit your local weigh station and, with your RV attached, weigh the front wheels of your tow vehicle (this will be your front GAW). Then, with your RV still attached, weigh your entire tow vehicle with four wheels on the scale. Take this weight and subtract it from the front GAW to find your rear GAW.
*Your rear GAW must never exceed your rear GAWR or your maximum hitch weight
Calculating Payload Capacity
GVWR – Your Vehicle’s Dry Weight = Payload Capacity
*The weight of your cargo and passengers should never exceed your payload
Calculating Towing Capacity
GCWR – GVW = Towing Capacity
*Your GTW should never exceed your towing capacity or your GTWR
Doing some simple calculations before making your final purchase can save you from a world of trouble in the future. Considering the question of what your vehicle can tow is only half of the work, the other half is doing the math and making sure your calculations are correct. A range of apps and websites are available to help you calculate your towing capacity so that you can feel even more confident and safe when towing your RV!