Defining GVWR, GCWR, and Other RV Weight Ratings
Understanding These Important Acronyms is Important for RV Owners
When listing the specs and features of an RV, manufacturers often use an array of confusing terms and acronyms. This is especially true when defining the weight of a motorhome or travel trailer and how it relates to towing.
For first-time RV owners, these acronyms can be especially confusing, but they do play an important role in understanding the capabilities of their vehicle. Here are some simple definitions to keep in mind while shopping for an RV or reviewing an existing model’s performance.
Gross Vehicle Weight Rating (GVWR)
An RV’s GVWR is the maximum allowable weight of the vehicle when fully loaded with fuel, fluids, cargo, passengers, and other items. This includes any aftermarket accessories or modifications, as well as the tongue weight of a dinghy vehicle.
The RV manufacturer determines the GVWR, which is the maximum weight for operating the vehicle without creating undue stress or strain. Exceeding this weight limit could result in damage to the RV or create dangerous driving conditions.
Gross Vehicle Weight (GVW)
The GVW is a vehicle’s weight at any given time, including all passengers, cargo, fluid, and other items. It is obtained by driving the RV onto a scale and recording the current weight. To avoid damaging the vehicle—and potentially voiding its warranty—the GVW should never exceed the GVWR.
Gross Trailer Weight (GTW)
Gross Trailer Weight is essentially the same as the Gross Vehicle Weight, except it applies to towables—like travel trailers and fifth wheels—instead of motorhomes. To determine the GTW, weigh the trailer on a scale without a tow vehicle. When hitched together, however, some of the weight is transferred to the truck, with the Gross Axle Weight and Tongue Weight (see below) playing important roles.
Gross Combination Weight Rating (GCWR)
This rating is the absolute maximum weight of the tow and towed vehicles, including cargo, passengers, fluids, and other items that are onboard. For safety purposes, RVers shouldn’t exceed this number, as the RV’s braking systems may not be able to slow down or stop in a safe distance.
Gross Combination Weight (GCW)
The GCW is the weight of a tow vehicle and towed vehicle—along with all cargo, passengers, and fluids, on a scale. For safety purposes, that weight should not exceed the GCWR as stipulated by the RV manufacturer.
Gross Axle Weight Rating (GAWR)
A vehicle’s GAWR represents the total amount of weight that is allowed on each axle assembly. The manufacturer assigns this rating and assumes that the weight is balanced across both tires. An RV’s component parts—including axles, springs, wheels, and tires—directly impact its Gross Axle Weight Rating.
Tire manufacturers assign their products a weight limit, which has a direct impact on the GAWR of a vehicle. If the load is too heavy, performance will suffer, leading to faster tire wear or an increased chance of a blowout. RV owners can compensate somewhat by increasing tire pressure on heavier loads. Adding 5-6 PSI to each tire can improve performance and handling.
Gross Axle Weight (GAW)
This is the weight supported on a single axle for a fully-loaded vehicle as obtained by weighing the RV on a scale. For safety purposes, the Gross Axle Weight should not be higher than the GAWR.
Unloaded Vehicle Weight (UVW)
The UVW represents the weight of a vehicle as it rolls off the assembly line at the factory, including all parts and accessories installed by the manufacturer. This rating does not take into account any cargo, passengers, or fluids of any kind, including fuel. Some manufacturers use the term “dry weight” when referencing the UVW.
Gross Cargo Carrying Capacity (GCCC)
An RV’s GCCC rating indicates how many pounds of cargo it can carry. That number is determined by subtracting the Unloaded Vehicle Weight from the Gross Vehicle Weight Rating. The remainder is the amount of weight that can be transported aboard the RV, including passengers, fuel, supplies, and anything else you want to bring with you on a trip.
Remember that adding aftermarket add-ons, such as awnings, a generator, or solar panels, will add weight to the vehicle and subtract from its cargo capacity. This isn’t usually a significant issue for most larger motorhomes and trailers, but it is something to consider when modifying an RV.
Tongue Weight (TW)
Tongue weight is sometimes referred to as the Tongue Load, Hitch Weight, Vertical Load Rating, or—in the case of a fifth wheel— King Pin Weight. This is the amount of the trailer’s weight that rests on the tow vehicle’s hitch when the two are connected. If that weight is too high, it can create issues with the braking and steering control. On the other hand, If the Tongue Weight is too low, it can cause instability at higher speeds or in strong winds.
Hitch manufacturers give their products a rating for the maximum weight they can safely tow. If the TW is significantly higher than that rating, it could malfunction, causing damage to the trailer and the tow vehicle. For trailers over 2000 pounds, the Tongue Weight should be approximately 10-15% of the GTW. That number climbs to 20-25% for fifth wheel models.
These acronyms represent the industry standards for classifying an RV’s weight and its impact on towing. By understanding their meaning and respecting these ratings, RV owners are safer on the road and put less stress on their vehicles.
Most of this information can be found on the vehicle’s Safety Compliance Certification Label, located inside the driver’s side door of a motorhome, or on the VIN sticker of most travel trailers. It should also be listed in your RV’s owner’s manual.