What's the difference between UVW, GVWR, and Dry Weight?

The Dirt Legal Guide to Understanding RV and Trailer Weights

Trailers play an important part of just about everything we do here at Dirt Legal. Looks, just because you have a tag on your ATVs, UTVs, and 2-stroke dirt bikes doesn’t mean you necessarily want to ride them cross-country to reach the trails. Of course, there are wildcard states like Colorado that will flat-out impound your legally-tagged OHV if you try to take it on public roads. 

Trailers like toy haulers are a great way to both move your OHVs and have a nice place to crash, and we highly recommend them. But there is a lot more to the equation than just grabbing a tri-ball hitch at Walmart and throwing a toy hauler on your F-150 (for the love of God, please get a truck that’s big enough for your trailer). You could be in for a rude awakening if you are over your weight rating. Let’s take a look at RV weights, trailer weights, and other vehicle weights so you know what exactly is going on. 

What Is the Unloaded Vehicle Weight (UVW)

Alright, so let’s start with a relatively simple concept which is the unloaded vehicle weight (UVW).  

Here’s exactly what the National Highway Traffic Safety Administration says about it: 

“The NHTSA defines "Unloaded Vehicle Weight" as:

The weight of a vehicle with maximum capacity of all fluids necessary for operation of the vehicle, but without cargo or occupants.”

And they go on to use this example:

“This term therefore results in low test weights based on the light pick-up body weight. As an example, a typical well equipped pick-up chassis with a 10,000 pound GVWR may weigh 4,400 pounds and its body may weigh 500 pounds for a total unloaded vehicle weight of 4,900 pounds. The truck chassis manufacturer would most likely test this vehicle at 5,000 pounds to insure S301 compliance.”

Sorry for all the copy pasta, but sometimes verbatim is the best approach. Our summary is basically this: the Unloaded Vehicle Weight is just the vehicle's weight as it is delivered from the factory. This includes the fluids necessary to operate but no cargo, no occupants, or any accessories removed that aren’t normally used (cargo and tool boxes, brush guards, etc). 

"Red Chevy Pickup Pulling Trailer and Carrying Dirt Bikes on Heavy-Duty Truck Bed Cover" by DiamondBack Truck Covers is licensed under CC BY-SA 2.0.

The UVW is also called the tare weight, a measure that is common to the trucking industry. 

Gross Vehicle Weight Rating (GVWR)

Now for a much more common weight rating: the gross vehicle weight rating (GVWR). This is a weight rating specifically for the vehicle itself, and it means that it is the heaviest the vehicle can safely be completely loaded. 

This includes the weight of the vehicle itself, full fuel, passengers, cargo, and tongue weight. 

There are plenty of negative consequences for exceeding the GVWR:

• Broken springs and excessive wear on suspension components

• Ineffective braking, and overheated brakes

• Overheating

• Transmission overheating (big time no-no)

•  Unpredictable and unusual behavior on the road

• Hot tires, which can absolutely lead to blowouts. 

How About the Gross Combined Weight Rating (GCWR)?

The GCWR is kind of the crux of this whole article. We are primarily talking about weight issues that pertain to a tow vehicle and a trailer. Like exceeding the GVWR, exceeding the GCWR is reckless and dangerous, plus it is really hard on your tow vehicle. 

"2014 Triple B Wild Horse Gather" by BLM Nevada is licensed under CC BY 2.0.

The GCWR is the maximum combined weight of a vehicle and trailer. So here is my proclamation to all of the urban bros who really think you can tow a loaded 37’ travel trailer with a ½-ton pickup that is full of passengers: just stop. I can all but guarantee you that you are exceeding your GCWR. Just buy the bigger truck! It costs about the same off the lot, and a bigger truck will only get marginally inferior fuel economy (it might actually be better with a load than the underpowered half-ton). 

Yes, it is a point of contention for me. As an avid camper who has driven quite a few thousand miles with a travel trailer in tow, I have seen so many people flying around with a ½-ton truck full of people towing a trailer that’s too big for it. You are just begging to have problems from this. You see how the rear end is squishing down? Yeah, you’ve got too much weight on that tongue. But more on that in a little bit. Buy enough truck for the heaviest thing you will tow. If you don’t have it, either upgrade the truck or downgrade the trailer.  

There are a number of different factors that make up the determination of the GCWR, which include:

• Vehicle make and model

• Engine 

• Transmission

• Drive axle ratio (this makes a huge difference)

• Optional equipment

• The type of trailer hitch is used (weight distributing, non-weight distributing, gooseneck).

It is up to you to do your research and figure out which one is correct. And again, it is always safest to err on the side of having a little too much truck than not enough truck. Bigger trucks are built with bigger springs, axles, and brakes, which are all important for towing. 

What is Dry Weight?

On to dry weight.

The dry weight of your vehicle is the weight of the vehicle completely dry, i.e., no fluids in it at all. This form of weight rating can apply to either the tow vehicle, or the trailer. 

Why Is It Important to Understand Weight Specifications?

Okay, so this question seems pretty straightforward, but it gets confused so often that we felt it important to address it. 

Your vehicle can only do so much. It can only haul so many people plus tow so much, and have so much luggage or cargo as well. 

Tips for Managing RV and Trailer Weights

Trailers can be a fickle thing. Balance is critical, and weights are even more important. Look, here’s the honest truth: trailers are and will always be a weak link. Something ALWAYS happens with a trailer. 

I have thousands of miles towing travel trailers, and guess how many issues I’ve had with the tow vehicles? Zero. And how many problems have I had with trailers? Boy, I don’t even want to go down that road. Over the years, automobiles have gotten more and more reliable, but trailers really haven’t changed a whole lot. 

If you want to avoid problems with your trailers, mind your weights. When it says the axles are rated for 3,500 lbs and you have two of them, don’t exceed that. RV trailers are notorious for this; the manufacturers ride a very delicate balance between weight and capability. And frankly, they do it to cut costs. Most trailers come off the lot with axles that are rated for basically the dry weight of the RV plus just a little more, meaning you really aren’t supposed to put much of anything in the camper. 

"A Chevy/GMC Hauling ATVs and Pulling A Camper Trailer" by DiamondBack Truck Covers is licensed under CC BY-SA 2.0.

It’s a little easier with flatbed trailers like auto hauler, deckovers, and equipment trailers. For these, generally the trailer weighs a lot less than an RV so there is ample room in the weight range to load cargo. Still, you need an empty weight for the trailer to know exactly what you can haul with it. 

For instance, if you have a 16’ car hauler trailer with twin 3,500lb axles and the trailer weighs 2,000lbs empty, your payload is 5,000lbs. Along with axle weights, make absolutely certain your tires are

1. Trailer tires and not car or truck tires. Trailer tires are made differently than car tires so you need to use trailer tires. 

2. Make sure they are the proper weight rating (Class C, D, E, etc). As a rule of thumb, I always go up a whole weight rating on my tires if it is available not because I intend to go overweight but because it’s nice to not worry about tires. They are always the weakest link on a trailer. 

Thoughts on Tongue Weight

My final thoughts on this topic are purely anecdotal from my own experience. If you are inexperienced at towing trailers, you should go to the manufacturer’s YouTube channel or blog and read up on how to load it properly. 

An improperly balanced trailer, particularly a bumper-hitch variety, is a dangerous trailer. It compromises your control over the trailer. In a lot of cases, the trailer outweighs the tow vehicle so balance is extremely important for control. 

But as you move weight up closer to the tongue, you also need to make sure you aren’t exceeding the tongue weight rating on your vehicle. This isn’t usually an issue on RVs because the trailer is built pretty well balanced and you aren’t parking a UTV, skid steer, or tractor on it. The amount of weight you can add toward the tongue is pretty minimal. But not so with equipment trailers and cargo trailers, so learn how to properly load them and pay attention. Towing a poorly loaded trailer can kill you. 

The Bottom Line

Do you need to know all this info about trailer weights? Maybe, maybe not. Where this is really important is when you aren’t using enough truck for your load. People who use undersized trucks to tow trailers are actually creating a lot of liability because they can and sometimes do exceed the GVWR and if something happens (which there is a heightened likelihood since they are using an undersized truck), they can be held liable. 

There is a lot to take in here in just a short time. Read up on what the different weight ratings mean. Make sure you fall within or under them. And when it comes time to register your trailer, save some money by going through Dirt Legal.