Before we dive any further, let’s define a few terms. These are commonly seen in the back of an owners manual, in online towing forums, and on stickers found in the driver’s door jamb.
Towing is defined as pulling a trailer behind a vehicle. It’s that simple. Whether you’re using the bumper, a frame mounted receiver hitch, or an in-bed hitch like a gooseneck or fifthwheel hitch, it’s all considered towing. Towing’s advantage is that cargo weight can far exceed what you could otherwise carry in the truck’s bed or in the rear of an SUV. That’s because the majority of the cargo’s weight is resting on the trailer’s axles. Only a small portion of weight is carried by the tow vehicle via the trailer’s tongue.
Payload is considered all the extra stuff you put inside your vehicle, whether it be passengers or a pile of rocks, that weight is all considered payload. The difference here is that the load is fully supported by the vehicle. Obvious examples include a truck with mulch or dirt in its bed or an SUV with five passengers and a week’s worth of luggage. In both cases, there is no trailer involved and all the cargo’s weight rests fully on the vehicle’s wheels. In general, a vehicle’s payload capacity is less than its towing capacity.
Gross Vehicle Weight Rating (GVWR)
The GVWR is a weight listed by the vehicle manufacturer that can be boiled down to the maximum amount a vehicle can weigh. This includes the vehicle’s unloaded curb weight, passengers’ weight, and cargo weight. If a truck’s GVWR is listed at 10,000 pounds and the truck weighs 6,000 pounds empty, then its payload capacity is 4,000 pounds.
Gross Combined Vehicle Weight Rating (GCVWR)
The GCVWR is defined as the maximum weight of a loaded vehicle and its attached loaded trailer. And like the other weight ratings discussed here, the vehicle’s manufacturer calculates this number. Let’s say a truck’s GCVWR is 15,000 pounds and it has a base curb weight of 6,000 pounds. That means the vehicle can safely handle an extra 9,000 pounds of cargo and trailer weight. However, it doesn’t matter (to a certain point) where that cargo is placed. If a passenger weighing 150 pounds sits inside the truck, that 150 pounds has to be subtracted from the truck’s then available GCVWR. Owners must still be mindful not to exceed the GVRW with in vehicle cargo and trailer tongue weight. (More on that below.)
The GCVWR is how automakers list the maximum allowable weight a vehicle can tow. By subtracting a vehicle’s base curb weight from its GCVWR, the automaker determines the available tow rating. Automakers usually publish tow ratings that account for a driver and one passenger, each weighing 150 pounds, and a full tank of fuel. So, if you’re going to tow a trailer that weighs exactly what your vehicle is rated to pull, you’d better leave the family and their luggage behind. Continuing with the example, if a truck has a 15,000 pound GCVWR and it weighs 6,000 pounds empty, plus it’s loaded with 4,000 pounds of cargo and passengers in the bed and cab, it can pull a trailer weighing no more than 5,000 pounds.
Trailer Tongue Weight
Helping to make things more confusing, we’ve got to account for the trailer’s tongue weight – or the weight the trailer exerts downward on the hitch. Generally tongue weight should be roughly 10 to 15 percent of the loaded trailer’s total weight – no more, no less. This tongue weight must be accounted for in the tow vehicle’s payload capacity. 5,000 pound trailer = 500 pounds tongue weight.
This added weight must not exceed the GVWR when added with the passengers and cargo already sitting inside. For example, our theoretical vehicle and its 10,000 pound GVWR offers 4,000 pounds of payload capacity. If you were to hitch up to that 5,000 pound trailer, its 500 pounds of tongue weight would reduce that 4,000 pound payload capacity to 3,500 pounds. Get the idea?
Now with all that out of the way, you’ve got the tools to understand how much your truck or SUV can haul and pull. However, it’s just as important to know where to find this information on your particular vehicle. Automakers place GVWR and GCVWR numbers on a placard inside the driver’s door jamb or inside the owners manual. Sometime you’ll have to do the leg work of figuring out what axle ratio your vehicle has or if your truck is equipped with optional engine oil and transmission fluid coolers that allow for larger loads. You’ll find that information usually on a sticker in the glove box that’s filled with manufacturer specific option codes. A quick internet search will reveal what your truck is equipped with. Being armed with that knowledge should allow you to make an informed decision about what your specific vehicle can properly handle.
Tow rating overview
This section should give you a good understanding of where to find your tow rating and what it means. We've pulled it from a great discussion on tow ratings written by Mark McNabb at TopSpeed.com. You can read the whole discussion here: Towing, Payload & GCVWR: What's it All Mean? If you have any specific questions about tow ratings or your vehicle, you can always reach out to us and we'll do our best to help.