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Please read our Loading a Caravan/RV page for more information.
A major item to consider -- after you have narrowed down your choices to a particular type of RV -- is weight capacity and whether it is adequate for your needs. Weight capacity for any RV (or tow vehicle) is measured by its gross vehicle weight rating (gvwr), which simply means the total weight allowed for the vehicle itself and anything added -- including people, fuel, water, propane and supplies. By itself, the gvwr is of little value; it only has meaning when it is compared to the actual weight of the unit when it's ready for use.
The uvw represents the vehicle's actual weight, minus cargo, water, propane and passengers. NCC is the amount of payload the unit can carry. Some manufacturers weigh every RV as it comes off the assembly line, while others estimate the weight. The uvw and NCC figures may not include factory or dealer-installed options, so even these figures are not etched in stone. You still need to add the weight of the unit's fresh water and propane, and possibly motor fuel if it's a motorhome, to arrive at a reasonably accurate cargo-carrying capacity.
Fresh water weighs approximately 8.4 pounds per gallon, and propane is 4.23 pounds per gallon. Gasoline weighs about 6 pounds per gallon, and diesel is about 8 pounds per gallon, so motor fuel must also be added to a motorhome's weight. Figure about 150 pounds per extra passenger in addition to the driver. Use the manufacturer's fluid tank-size specifications to add the proper amount of fluid weights to the RV, by multiplying the tank capacity in gallons by the pounds/gallons figures above.
Finally, gross combination weight rating (gcwr) is the maximum total combined weight of any vehicle and its towed load, which can be a truck and trailer or a motorhome and dinghy car, for example. Gcwr is another figure that must not be exceeded if you are to be driving a safe, reliable RV combination. Weight also has a major influence on economy of operation, specifically regarding fuel consumption. While overall size has an important bearing on livability, it also has a strong influence on total weight. The larger the unit, the heavier it usually is, and the more fuel it will burn getting from point A to point B. So if you plan a lot of travel and fuel costs are important, select a smaller unit, which will also be easier to drive.
When something breaks because of a safety problem, it costs a lot of money to repair it. The purpose of the page is to help resolve the Overload Problem. It's serious! 64% of the RVs on the road exceed the weight rating.
A critical safety issue all RV'ers need to be
become more informed about is "Weights & Balance". But, just what
is meant by "Weights and Balance"? Why is this term becoming of more
interest to RV'ers? The answers are fundamental; Saving time and money, and
safety! Saving you time and money, and ensuring your safety. Pretty solid
reasons for most of us to realize the importance of Weights and Balance, not as
a fad, but for survival.
"Weights & Balance" pertains to the weight of an object with all
of it's component parts, and the distribution of that weight. Although weight
and balance applies to many fields, I will limit the discussion to RVs.
Terms RVers Should Understand.
- Gross Vehicle Weight Rating (GVWR): The most that your RV or truck should ever weigh -- fully loaded. These numbers are established by the manufacturers of the vehicles.
- Gross Axle Weight Rating (GAWR): Each axle has a separate rating. It assumes the load is equal on both sides -- which virtually never happens. 10% of the overweight RVs exceed a tire rating without exceeding GAWR. That happens because of a load imbalance in the RV.
- Gross Combined Weight Rating (GCWR): Not found on the data plate. It's a function of the vehicle doing the towing, and it can be hard to find. Total of truck and trailer weight.
- Unloaded Vehicle Weight (UVW): How much the vehicle weighs when it leaves the factory.
- Net Carrying Capacity (NCC): Subtract UVW from the GVWR and the result is what can be added to the factory weight.
- Axle Weight Rating (AWR).
Proper loading of, and weight distribution in,
your rig can prevent premature tire failure, suspension problems, broken axles,
burned-up transmissions or differentials, and other breakdowns. In addition to
the cost of repair parts and labor, there could be expensive unscheduled stays
in hotel/motel rooms, and the associated meals, towing, etc. Of course, the
worst case scenario would be a wreck resulting from a blowout, or perhaps loss
of control.
There is a difference between "load" (actual weight applied) and
"load rating" (maximum engineered design load limit). Gross Vehicle
Weight Rating (GVWR) is determined by the manufacturer in the design of the
unit. GVWR cannot be changed; that is to say, the addition of heavier components
does not change the legal GVWR of your vehicle. Any load exceeding these
manufacturer's rating values is both unsafe and illegal; and perhaps immoral,
for in doing so you consciously put other people at risk of life and limb.
For a long time there has been extensive discussion, even heated debate,
concerning the Weight Rating tags affixed to Recreational Vehicles by the
manufacturer. The industry is being responsive to consumer demands for accuracy,
but the consumer and the manufacturers still must reach understanding of what
the weight rating terms are describing. The Recreational Vehicle Industry
Association (RVIA) requires all member manufacturers to properly label each RV
that leaves the factory. However, this is voluntary compliance and not all
manufacturers are association members. There are many RV enthusiasts that don't
have either the knowledge or the training to interpret weight ratings. Nor
should they have to if they could depend on the salesperson to candidly
represent the product. That salesperson should be ready to inform a customer if
they are making a bad choice. The discussion of the RV load matching the
chassis' or tow vehicle's capacity needs to take place during the sales process.
We, the consumer, need to be responsible too, and not be impulsive or
unrealistic in our expectations or demands. We must educate ourselves about what
all the numbers on the nameplate mean. If your intended purchase is too heavy
for your tow vehicle or chassis you will be faced with continued frustration,
frequent major (read that as expensive) repairs, and in general a frustrating
and expensive long term proposition, instead of the fun and relaxation that the
RV Lifestyle should be. The following terms do not have consistent usage in the
RV marketplace. Have a discussion with the salesperson to understand exactly how
they are using these terms.
"Dry weight" is a very imprecise term. Some manufacturers say it means "nothing wet" in it. Others will say it's without options. Dry Weight is the empty weight of the vehicle or trailer. Dry weight may or may not include the weight of appliances, slide outs, etc.
Wet Weight is the weight of the vehicle with fuel, oil, and coolant onboard. Wet weight should, but may not, include the weight of the LPG (propane or butane) in the tanks, and fresh water. (Water weight is 8.34 lbs./U.S. Gallon so a 100 Gallons weighs 834 lb.)
Curb weight, or Net Weight should be the weight of the unit as it is sitting on the lot, without the personal load you will be adding.
Payload Capacity is
the difference between the actual weight and the GVWR of the vehicle or trailer.
Options and accessories may add weight that is taken from the payload capacity,
leaving you with less margin than you think you have. Ask the dealer to provide
proof of the units weight before you finalize the sale. Then do the math and
calculate what the remaining payload capacity really is.
Gross Combination
Weight Rating (GCWR) is another design capacity of a towing vehicle. It
means the maximum weight rating of a towing vehicle and a towed unit in
combination. GCWR takes into consideration such things as the drive train
capacity (i.e. engine, transmission, drive shaft and differential), gearing,
braking capacity, suspension, and axle loading. When integrating a tow vehicle
with a trailer, either a fiver or travel trailer, add the GVWR of the trailer
with the GVWR of the tow vehicle. If they add up to more than the GCWR of the
tow vehicle it a bad match. The only solution is to pick a lighter trailer or a
bigger tow vehicle. The same applies to a self contained unit and a towed unit,
either four wheels down or on a dolly. Each of the big three pickup truck
manufacturers (Chevrolet, Dodge and Ford) state in their literature a
"Trailer Towing Capacity" as well as an alternate method for
determining maximum allowable trailer weight. The published towing capacity is
maximum allowable trailer GVWR, but usually requires extra optional features -
called a towing package, and other options such as a particular engine or rear
axle ratio.
You have probably already seen articles relating to weighing your rig; front-to-back and also side-to-side. This is an important task to take care of when you first acquire and load your RV, whenever you change equipment that could affect the vehicle's weight (RV and/or Tow Vehicle), and periodically thereafter - the "period" depends on how much you travel. If necessary, reconfigure your rig, or reload it, and then have it weighed again. You may have to repeat the process until you get the weights within required limits and distributed correctly. It is surprising how much weight distribution changes just through usage. Things get stowed in different places; new things are acquired as you travel, some things are used up or taken out, etc. "Weights and Balance" is dynamic; that is, it changes.
How to Determine if your Vehicle exceeds its Gross Vehicle Weight Rating (GVWR)
Determine the GVWR by looking on the label located on the driver's door post of most vehicles. Enter that figure into the table below.
Determine the NET WEIGHT by taking an unloaded vehicle to a public scale and getting it weighed. Enter the weight into the table below.
| GVWR | ______________________ |
| (Minus) NET WEIGHT | - _____________________ |
| Maximum Allowable Load = | ______________________ |
| Load to be Carried = | - ____________________ |
Add all of the following items:
-
Weight of passengers carried
-
Weight of all fuel, water, oil and equipment (tools, etc.)
-
Weight of all after-market items installed
-
Weight of any cargo
-
Weight of other miscellaneous items to be carried
Enter the total of all the above to the table above in "Load to be Carried".
Subtract the "Load to be Carried" from the "Maximum Allowable Load".
If the "Maximum Allowable Load" will be exceeded, you must reduce the weight of the "Load to be Carried" in order to remain in compliance with your vehicle's Gross Vehicle Weight Rating.
For optimum results, reduce the "Maximum Allowable Load" by 75% and stay within that limit to allow a margin of safety.
When integrating a tow vehicle with a trailer, either a fiver or travel trailer, add the GVWR of the trailer with the GVWR of the tow vehicle. If they add up to more than the GCWR of the tow vehicle it's a bad match. The only solution is to pick a lighter trailer or a bigger tow vehicle. The same applies to a self contained unit and a towed unit, either four wheels down or on a dolly.
State Laws require that any towed vehicle exceeding a specified weight, usually about 1,000 to 1,500 lb.., must have it's own braking system. The alternate method for determining allowable trailer weight requires that you know the loaded weight of the tow vehicle and the loaded weight of the trailer (something we don't know when we are on the dealer's lot). The sum of these loaded weights must not exceed the tow vehicles GCWR. If you use the alternate method for computing allowable trailer weight, you risk not being able to load the tow vehicle more than the weight you used when you calculated the allowable trailer weight. There are also limits placed on the tongue or "hitch weight" when towing a travel trailer. Plan on 12% of the trailer's GVWR as hitch weight; actual hitch weight when connected should fall between 9% and 12% of the trailer's loaded weight. Fifth-wheel pin weight comes out of the trucks payload capacity, and you should plan on 18% of the fiver's GVWR. With the fiver hitched-up the pin weight should be between 15% and 18% of the trailer's loaded weight. No combination should ever exceed the tow vehicle's Gross Axle Weight Ratings, front or rear.
Front-to-back distribution of a two axle,
six-wheel "straight rig", that is a non-towing vehicle, when loaded,
should be 30% on the front axle and 70% on the rear axle. For a towing vehicle
of two axle, six-wheel configuration pulling a 5th wheeler as a semi-trailer,
the ideal distribution would be 20% GCW on the front axle, 40% GVW on the rear
axle, and the remaining 40% GCW on the trailer axles, however, practical
distribution is 15% on the front axle, 31% on the rear axle, and the remaining
54% GCW equally divided on the trailer axles. A rig that is not relatively equal
side-to-side will not ride or handle well. If there is an out of balance
condition in either direction (absent a broken suspension component or flat
tire) it is due to improper load distribution. Side-to-side imbalance could be
either the result of incorrect loading or poor manufacture. Strong evidence why
it is best to weigh before you buy.
Most travel trailers should use a load
leveling (weight distribution) hitch. Before hooking up measure the distance
from some convenient reference point on the tow vehicles front and rear bumpers
to the ground. Then connect the trailer and start loading the hitch torsion bars
one chain-link at a time, keeping the chains equal on each side. As the load on
the torsion bars is increased, the rear of the tow vehicle comes up and the
front goes down. When the front and rear bumpers are as close to the reference
measurement as you can get (and it should be within a half-inch at the front
bumper) the hitch is tensioned correctly.
A self-contained unit's wheelbase to length
ratio can be used to judge how well a vehicle will ride and handle. A short
wheelbase makes for easier maneuvering while a longer wheelbase increases high
speed stability and ride comfort. However, when comparing Length Overall (LOA)
to wheel base length, a long body on a short wheel base is not desirable..
Dividing the wheel base (Inches) by the vehicles length (Inches) it is favorable
to have a ratio of 0.54 (54%) or more. Long haul busses, such as Greyhound
buses, have a 0.66 ratio for both comfort and SAFETY. Yet another issue is the
center of gravity. The higher the CG the less stable the vehicle will be in
turns and curves, or in cross winds. Calculation of the CG is complex; so ask
the manufacturer to provide this important data.
No matter how many times you may have gotten away with improper vehicle
integration or overloading in the past, or what you may have seen others doing,
to be SAFE you need to respect the engineering design limits. These ratings are
based on a lot more than what I can cover in this article, but the bottom line
is expressed as the weight ratings published by the manufacturers. Be safe -
live by them.
As of September 1, 1996 , RVIA member's Motorhome data plates have been required to show, in addition to GVWR, the UVW, the NCC, and the GCWR. Unfortunately, however, estimates are allowed, and the data plates can be difficult to find even though the regulations state, "post in a conspicuous place". The biggest problem not addressed is weight distribution. The RV might have 2,000 pounds of NCC, but it might all go over the front axle, thus causing a violation of an axle or tire rating. A secondary problem is that the UVW is measured at the factory. If a dealer loads it up with options, the weight of these additional items will not be reflected in the data stated on the plate. But smart RV buyers can and should inquire into the total weight of all dealer-installed options. The towing guide will show you what a truck can pull -- unloaded, with no options, a 150 lb. driver and no passengers! Weigh it before you pay for it. A reputable dealer will allow this.
Please read our Tow Vehicles page for more information.
Truck stops (Flying J) are a good choice. The charge is $5 -$8 for the first weighing, and less for a subsequent one. Make sure the scales are certified. If they are not too busy, a state weighing stop, (Oregon for example), will allow you to weigh.
A trailer hitch has two numbers on the data plate. One refers to trailer weight,
the other refers to vertical weight. Trailer tow bars should have similar
information. Trailer balls might have "5,000 pounds" on it, but it
might be fit into a 2,000 pound rated receiver.
Exhaust brakes for diesel engines are a superb safety feature. For towed cars,
there are three good devices on the market which will engage the brakes on the
towed vehicle. Electric trailer brakes are troublesome, and one never can tell
how they're working. From Camping World, one can purchase a $20 device which
will measure amperage to the trailer brakes, and you can visually check the
status of your trailer brakes.
Hitch Weights / Tongue Weights
There are several different terms to describe an RV's actual weight. Here are a few useful terms and definitions to help you.
| UVW | (Unloaded Vehicle Weight) the total weight of an RV as it sits (THIS CANNOT BE DETERMINED BY THE STICKER ON THE OUTSIDE FRONT CORNER OF THE TRAILER.) |
| GVWR | (Gross Vehicle Weight Rating) The maximum weight that the axles or the tires will carry. It is the lesser of the axle carrying capacity or the tire carrying capacity (THIS IS DETERMINED BY THE STICKER ON THE OUTSIDE FRONT CORNER OF THE TRAILER.) |
| NCC | (Net Carrying Capacity) This is the actual amount of cargo allowed. This is in simplest terms, GVWR-UVW=NCC |
| Hitch Weight | The weight on the hitch. |
| GVW | See GVWR |
| Carrying Capacity | See NCC |
| Gross Dry Weight | See UVW |
| Dry Axle Weight | The weight of the trailer when the RV is on the hitch, in other words, UVW-Hitch Weight=Dry Axle Weight. |
Words of wisdom
Many people make the mistake of using the GVWR as the weight of the RV. Some RVs
can have a NCC of 3000 pounds are more. You could load a couple of popups in
these if you could fit them through the door!
Most light-weight RV manufacturers do not include the weights of the available options in their the UVW (like an AC, Awning,etc.). You must add that weight to the UVW to get the true weight.
Vehicles have a hitch weight limit and a tow limit. A travel trailer can have some to all of it's hitch weight transferred to the front wheels of the tow vehicle by using an equalizer hitch (a.k.a. head & bars). You can actually exceed your hitch weight with a properly set up equalizer hitch. It is not, however, recommended that you exceed your tow rating.
Weighing Your Loaded Caravan / RV
Refer to your local directory to locate a public weigh station. The following weighing procedure will help you determine whether your loaded motor home (complete with cargo, fluids, passengers, and driver) is within GAWR and GVWR limits. When you arrive at a weigh station, the attendant will guide you through the correct positioning of the motor home on the scales.
1. Center the front wheels on the scale platform and take a reading. This is the front Gross Axle Weight (Reading 1).
2. Center the entire vehicle (all axles) on the scale and take a reading. This is the Gross Vehicle Weight (Reading 2).
3. Center the rear wheels on the platform and take a reading. This reading is the rear Gross Axle Weight (Reading 3).
4. Compare Reading 2 with the GVWR of your vehicle. If the reading exceeds the GVWR rating, you will have to reduce the total vehicle load.
5. If Reading 2 is less than the GVWR of your vehicle, check Readings 1 and 3 to verify that each is less than its respective GAWR. If either exceeds the GAWR, redistribute the load and reweigh.
6. For a tag axle, center both rear axles on the scale platform and take a reading. Compare with the sum of both the rear (tag) and the intermediate (drive) GAWRs.
Periodically reweigh your motor home. Loading and weight patterns will change according to use.
NOTE: This online manual is a work in progress and is subject to change at any given time. It is also a generic peace of work and is meant only as a general guide. Each Caravan/RV is distinct and individual in it's own right, do not take anything written here literally as it may or may not apply to the exact Caravan/RV you will be using.