Wheel Position Weighing

Why should I have my RV weighed?

To know if your RV exceeds the Gross Vehicle Weight Rating (GVWR) or Gross Axle Weight Ratings (GAWR) assigned by the manufacturer. Exceeding these ratings can cause premature wear and tear on the vehicle's components. The RV may have failures or need repairs due to excessive weight, although the weight factor may not be clearly evident. In the worst case, an overweight situation creates safety hazards.
To know if your motorhome and towed vehicle or your trailer and tow vehicle exceed the Gross Combined Weight Rating (GCWR) assigned to your motorized vehicle (the motorhome, or the tow vehicle in the case of a trailer). Exceeding the GCWR can have legal and safety consequences.
To know if you need special licensing for the state in which your vehicle is registered.
To know if your RV tires are overloaded and have the proper inflation pressure for the loads on the tires.
To know if your RV tires have the proper inflation pressure for the loads on the tires

Why should I have my RV weighed by wheel position?

The ONLY way to properly weigh your RV is by wheel position. Your tires and wheels are the foundation of your RV, and each has a maximum weight rating. An overloaded tire (a.k.a. an underinflated tire) is the number one cause of rapid tire failure (most often referred to as a "blowout").
It is possible to be within your Gross Vehicle Weight Rating (GVWR) and your Gross Axle Weight Ratings (GAWR), and still overload a tire at an individual wheel position.
Unless you know the load/weight carried by each wheel position, you have no way to know the proper inflation of your tires. Improper inflation leads to improper wear, reduced life of the tire, and greater potential for rapid tire failure.
The major tire manufacturers recommend wheel-by-wheel weighing. From the Michelin North American RV Website: "For RV use only, Michelin displays tire loads per axle end in the load and inflation tables, as we recommend weighing each axle end separately and using the heaviest end weight to determine the axle's cold inflation tire pressure."
From the Goodyear Recreational Vehicle Tire & Care Guide:
"Goodyear also recommends weighing each wheel position of your vehicle." and "A loaded axle may be within its rating, but could possibly still be overloaded on one side."

Why should I have my RV weighed by RVSEF?

RVSEF developed the industry standard procedures for RV weighing that are accepted by tire manufacturers, RV manufacturers, and the RV Industry Association.
RVSEF provides a detailed weighing report that compares your RV's ratings with actual weights collected. You receive more than just numbers. You receive an analysis and you have the opportunity to speak with RVSEF personally about your results.
RVSEF is concerned with your safety and the enjoyment of your RV. We work with you from the standpoint of education and weight management. There is no weight police attitude. We help you work with what you have.
RVSEF, in addition to providing you with personal results, supplies summary results to the RV industry to help manufacturers make better RVs. No other weighing organization has 25 years of results and over 38,000 records. And no other weighing organization has had as much influence on the RV industry regarding safety.
RVSEF is a 501(c)(3) non-profit organization that relies on donations and its weighing service as its main sources of revenue.

So, how does the RVSEF weighing process work?

First, we ask you to complete a RV work sheet based on the type of RV you have (motorhome or towable). This is part of our education process, so you learn and know important weight and tire details about your RV. Of course, we can help you if need some direction.
An important part of the work sheet is to tell us what air pressure you run in your tires.
We need to get the work sheet in advance, so we can go over it for accuracy. Also, we need the information to prepare your weigh report.
Once you arrive at our designated weighing site which we have pre-selected for easy access and levelness, we receive payment.
We use 3/4" tall 20,000 pound scales that are the same portable scales used by many local, county, and state deparments of transportation enforcement offices. They are marked in 50-pound increments. The low profile makes them easy to climb and, they are tested and checked annually.
For motorhomes, we pull you up on the scales, take the readings, write down your numbers, and then you receive a detailed analysis report.
For tow vehicle/towable combinations, we follow the same procedure. The big difference is we have to weigh the tow vehicle separately to properly determine pin weight or tongue weight. When we weigh the tow vehicle separately, it's very important that it be loaded the exact way as when it is weighed with the trailer (i.e. fuel, passengers, cargo, etc.).

Why can't you just weigh my RV at the camp site?

We never set appointments that way because too often the site isn't within our tolerance of being level. If it's not level, the weights will be inaccurate (and it can be significant). Then we have to have you move anyway. So, as a matter of standard practice, we pre-select a proper weighing site we know will work.
For RVs with air suspension, it is important that the RV be driven to the weighing site so the air suspension can level the cabin or living area and accurate weights can be measured. The intention is to have the RV in a position that simulates the position of going down a level road.

Can't I just get weighed at a truck stop scale?

Yes, you can. But there are several factors why it is not the best method.
You cannot get individual wheel loads on a truck scale. Here is a quote from the CAT Scale website:
"Please note: Our scales can give you axle weights and a total gross weight, however, they cannot weigh each corner of the vehicle. We cannot provide individual wheel weights and, to prevent damage to your vehicle as well as our scales, do not allow that type of weighing."
You can get total weight and perhaps axle weights, but as we mentioned earlier, the only proper way to weigh your RV is by wheel position.
If you have a tandem axle on your motorhome or two or three axles on your trailer, you often cannot separate out the axles to get accurate individual axle weights.

I've seen numerous diagrams and calculations on the internet showing how to weigh my RV and get wheel positions weights on truck scales, grain elevator scales, moving company scales, and other places. Can't I just do that?

Well, in theory, you can. However, from a practical standpoint there are some hurdles.
First, the largest truck scale network in the world, CAT scale, doesn't allow it (see quote in answer to prior question).
Often the larger scales are suited to much heavier weights. When you start weighing just parts of the RV, the inaccuracies multiply.
Often there barriers place at the scales to keep this process from being done. Additionally, there often isn't enough level room on the sides or ends of the scales to weigh your unit with the unweighed protion of the RV (or combination vehicle) off the scale (as is shown in these diagrams). This compromises the accuracy of the weight readings for the wheel positions on the scale.
Finding a place that will allow you to get permission to take several readings is a challenge. Truck stops and truckers certainly don't want RVers clogging up the scales with this process.
When you attempt to determine individual wheel position weights in this fashion, half the weights are calculated rather than measured. There are numerous factors which can make those calculations incorrect.

But isn't weighing on a platform scale to get a total weight better than nothing?

Assuming you understand the limitations, yes. Overall weights on a platform scale are a good starting point.
If you just can't find a place to get your RV weighed wheel-position-by-wheel-position, weighing on a platform scale gives basic starting information. Then you can get wheel-by-wheel weighing done when you have the opportunity.