Preparing to tow a camper or trailer can be a little confusing, especially if you’re not very familiar with GCWR and GVWR. What does GCWR mean and how is it different from GVWR? What else should you know about tow ratings? Read on to find out more about the meaning of GCWR and GVWR.
What is GCWR?
The GCWR (gross combined weight rating) is the maximum recommended weight of the vehicle, the trailer attached to it, and all of the passengers and cargo in both vehicles. In a way, the GCWR describes the entire weight of the towing system. The GCWR is also sometimes called the gross combined vehicle weight rating (GCWR).
Is the GCWR the Same as Trailer Weight?
The GCWR isn’t the same as the trailer weight. As previously mentioned, the GCWR describes the weight of the entire towing system.
GCWR vs. GVWR: What’s the Difference?
While the GCWR accounts for the weight of the entire towing system, the GVWR (gross vehicle weight rating) describes the maximum recommended weight of the vehicle, its passengers, and cargo. It doesn’t include the weight of a trailer.
That said, does the GVWR include the payload? The short answer is no. The payload rating of a vehicle is the total weight a vehicle can haul and is calculated by subtracting the vehicle’s actual curb weight from its GVWR.
You can find the GCWR, GVWR, and other towing-related information for your vehicle in your owner’s manual, driver-side door sill, or on the vehicle manufacturer’s website.
How Is GCWR Calculated?
The vehicle’s manufacturer typically provides the GCWR of a vehicle. You can check your vehicle’s owner’s manual and other resources provided by the vehicle manufacturer to find out your vehicle’s actual tow ratings.
If you’re going on a trip and you’re not sure if your towing setup is within the GCWR of your vehicle, you can fully load everything up and drive to the nearest certified scale. Otherwise, you’ll have to calculate the vehicle’s curb weight, as well as the weight of all the occupants and cargo.
Is It Safe to Tow More Than My Vehicle’s Tow Rating?
No, it’s not safe to exceed your vehicle’s towing capacity. Going over your vehicle’s maximum towing capacity can strain your engine and transmission. It can also wear your brakes, tires, and chassis. Remember that a vehicle’s brakes are typically only rated for the GVWR, not the GCWR. If the gross combined weight of the tow vehicle and trailer exceed the GVWR, a separate set of trailer brakes are required.
Towing more than what your vehicle can handle can put you, your passengers, and other people on the road in serious danger. Make sure to always stick to your vehicle’s tow ratings.
If you subtract your vehicle’s GVWR from its GCWR to find the tow rating of your vehicle, you might find that the result is a bit different from the vehicle’s advertised tow rating. It’s recommended that you stick to the lower number between the two to be safe.
Can You Give Me a Sample Computation?
Now that we know the meaning of GCWR and GVWR, we can do a sample computation to see how these ratings work and are calculated. Let’s use the 2020 GMC Sierra 1500 with a 4.3L engine and a regular cab as an example. This truck’s maximum GVWR is 6,800 lbs and its curb weight (weight without passengers or cargo) is 4,520 lbs. It also has a maximum payload of 2,240 lbs, a GCWR of 12,800 lbs, and a maximum towing capability of 7,900 lbs.
| Maximum Value | Computed Value | |
|---|---|---|
| Gross Vehicle Weight Rating (GVWR) [Vehicle + Passengers + Cargo] | 6,800 lbs | – |
| Gross Combined Weight Rating (GCWR) [Vehicle + Passengers + Cargo + Trailer and its cargo] | 12,800 lbs | – |
| Curb Weight [Unloaded weight of the vehicle] | 4,520 lbs | – |
| Payload [Total weight of any cargo and passengers] | 2,240 lbs | 2,280 lbs [GVWR – Curb Weight] 1,940 lbs [GVWR- Curb Weight – Total Passenger Weight] |
| Towing Capacity [Maximum weight a vehicle can tow] | 7,900 lbs | 8,280 lbs [GCWR – Curb Weight] 7,980 lbs [GCWR – Curb Weight – Total Passenger Weight] |
| Gross Trailer Weight [GCWR – GVWR] | – | 6,000 lbs |
If we subtract the curb weight from the GVWR, we get an approximate value of the payload, which is 2,280 lbs. While this value is close to this model’s 2,240 lbs of actual maximum payload, it doesn’t mean that this truck can handle 2,240 lbs of cargo in the bed at all times. You also need to factor in the total weight of the passengers inside the cab. If you have two 150-lbs passengers in the cabin, this reduces the truck’s available capacity to 1,940 lbs.
As for the towing capabilities of this truck, if we subtract the curb weight from the GCWR, we can get 8,280 lbs. If we subtract the driver weight from that figure to comply with the SAE J2807 regulations, we can get real close to the Sierra 1500’s maximum tow rating of 7,900 lbs.
If we subtract this model’s GVWR from its GCWR, we can get 6,000 lbs of gross trailer weight. This means that if you plan on running your vehicle at maximum GCWR, you’ll need to make sure that your trailer weight does not exceed 6,000 lbs at maximum payload. Alternatively, you can choose to tow heavier than that as long as you have no payload. Note that you’ll still need to account for all the passengers in your truck first before you max out your payload and towing capacities.
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