GVWR vs GAWR vs GCWR: How to Measure Towing Capacity
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According to the Washington Post, just about a million Americans now live in an RV. It’s not because of the pandemic or lack of housing but because they find this to be one of the best and most comfortable ways to see the country.
Granted, there are different types of RVs, some that need towing and others that ride on cars; campers tend to call for towing, which means that there are at least a million people who need to understand the terms GVWR vs GAWR vs GCWR fully. That’s not to mention the more than 7 million families that own an RV and occasionally go on road trips in those vehicles.
If you have ever been interested in seeing the countryside in the comfort of what might feel like your own home, then there is a good chance you have thought of either renting or buying one of these vehicles.
However, towing is not just all about RV enthusiasts. People who own fishing boats, horses, work in farms, work in trucking, etc. All people should be interested in understanding the difference, if any, between GVWR, GCWR and GAWR.
Why Do Terminologies Such as GVWR, GCWR and GAWR Matter?
Statistics from the NHTSA shows that there are just about 50,000 towing related road accidents each year. While there are many varied reasons why these accidents occur, the truth is that many of them would be easily avoidable if the drivers involved understood how overloading or towing overweight trailers negatively impacts their vehicle’s braking capacity and balancing on the road.
Thankfully, that number has stayed relatively low due to the strict regulations and guidelines put out by the FMCSA on towing on American roads. Within these strict regulations are acronyms such as GVWR, GCWR and GAWR.
While they might seem very similar to novice towing enthusiasts, these acronyms are uniquely different, and understanding them, as well as how each affects your towing weight and safety, will not only help you stay on the right side of the law when towing but also help keep you safe while doing so.
What is the Definition of GVWR?
GVWR stands for “Gross Vehicle Weight Rating.” It’s essentially a unit used for a range of vehicles, from lightweight pick-ups to heavy-duty tractor-trailers that are legally allowed on the roads.
Since this unit governs such a wide range of vehicles, it’s logical that it would be attributed differently to every single type within its purview. Despite all that, the key aspects of GVWR remain the same and covers:
- The base curb weight of the vehicle in question when it has all the standard equipment loaded (what comes standard from the manufacturer)
- The overall weight of every other optional trailer accessory that doesn’t come standard from the manufacturer
This second section is extremely important as customizations and accessories can pack on a great deal of extra weight to any vehicle. It should also be noted that this includes the weight of the person operating the vehicle and any other passenger riding in the vehicle.
Because every driver is different and every RV or towing enthusiast has their own preferences as far as accessories are concerned, it’s logical to assume that arriving at this standard weight rating would be problematic. That is why there is a simple formula that works for every single vehicle within the same weight class:
GVWR = Trailer Capacity + Trailer Weight
- Trailer capacity = the maximum weight that the trailer is designed to hold
- Trailer weight = the combined weight of every single item being hauled by the trailer
The GVWR is determined by each manufacturer and never changes unless there is a recall of the particular trailer in question. The issuing authority, such as the U.S Department of Transportation, makes a formal change.
What is the Definition of GCWR?
GCWR stands for “Gross Combined Weight Rating.” This is the maximum towing weight of a vehicle. The difference between this and the GVWR is that it is the number determined by the manufacturer that covers the absolute maximum weight the vehicle is able to tow. The GVWR can change base on circumstances such as number of passengers and payload but the GCWR is a fixed number.
The GCWR has to take several factors into account.
- Vehicle suspension
- Frame strength
- Axle power
- Overall towing capacity
The total of the GCWR will be the maximum amount of weight of the vehicle itself plus passengers, cargo, a trailer and its cargo as well. All of this information is important in determining two very important factors. One is the towing capacity of the vehicle and the other is its ability to safely brake at capacity.
What is the Definition of GAWR?
GAWR stands for “Gross Axle Weight Rating.” It’s essentially a standard unit applied to every vehicle, but it’s specifically focused on vehicles built with multiple axles. These start from a small car up to multi-axle trailers.
Much like the GVWR, the GAWR is determined by the vehicle manufacturer, and it shows the total weight that can be safely placed on each axle of the vehicle in question. You will most likely have different GAWR figures in the same vehicle as the front axle, and the rear axle can take on different amounts of weight, respectively.
The GAWR of your vehicle will remain constant unless there is a recall of the vehicle of a governing authority issues changes in the guidelines.
If you are unsure where you can find your vehicle’s GVWR or GAWR, you can either look it up on the manufacturer’s website for your specific vehicle type, or you can check the inside of your vehicle door frame at the manufacturer’s placard.
Also Read: How to Back Up a Boat Trailer
What Are the Main Differences Between GAWR, GCWR and GVWR?
To the untrained eye, these three weight ratings seem very similar. However, there is quite a bit of a difference between the three, and it has everything to do with how the respective weight capacities are handled.
For example, a critical look at the GVWR will show you that it specifically deals with the trailer’s weight being towed. This weight is first looked at as is with just the standard equipment from the manufacturer. This means that all other variables, such as the passengers’ weight in the trailer and the load, are removed from the equation.
The second part looks at all other weight added on, including the passengers and any other personal items, loads, and modifications.
The GAWR, on the other hand, has everything to do with the amount of weight that can be placed on each axle and often varies within the same trailer. This variability in weight from the front axle and the rear axle often depends on the placement or the number of axles on the trailer in question.
GAWR is often confused with another similar acronym, GAW or “Gross Axle Weight,” which is a number that changes constantly depending on how much load is added on or taken off the trailer in question.
It should be noted that the GAW can never be higher than the GAWR; it should always remain below or equal to it. That’s why it’s important to always check your vehicle’s data plate to get the right GAWR to remain compliant.
The GCWR takes into account all weight that is going to be applied to the vehicle and the trailer when loaded with cargo. This is the absolute maximum weight the trailer and vehicle can handle at one time, including cargo and passengers. It is a number that will not change.
As you can see, despite the fact that all three of these acronyms have a lot to do with the vehicle’s towing weight and safety, they are each rather unique in what they specifically measure. The GVWR and GCWR are more of big picture units that tells you just how much you can load onto your trailer while the GAWR tells you the maximum weight related to your vehicle’s axles.
All three are extremely important and unchanging numbers that will determine your compliance when towing on the roadways. That’s why understanding them is absolutely vital for every fleet owner or RV enthusiast.