Should I Weigh My RV?

What’s my RV weight? Should I weigh my RV? Let’s explore this topic.

There are many weights: dry weight, curb weight, axle weight, vehicle weight, towing capacity, trailer weight, and total combined weight.

How does one know what each weight category means? Beyond that, how does one determine the weight of their RV combination? Let’s just answer one question at a time.

Should you drive into a truck weigh station that’s located along the interstate to weigh your RV? No! They would probably be rather upset if you did. Those weigh stations are intended for commercial trucking only. They also are not likely to be able to provide you with a printed weigh ticket containing the information.

Driving a Class A motorhome on Newfound Gap Road in Great Smoky Mountains National Park, Tennessee © Rex Vogel, all rights reserved

CAT scales

CAT scales are located at numerous truck stops. Their website has a listing of all facilities.

Recently the fee to weigh was $12.50 plus $3 if you need to do a re-weigh. The process is fairly simple but you could always park first and go inside to ask about the procedure at the service desk.

CAT scales are intended for truckers who need to know the separate weights of the front axle (or steer axle), the drive axle(s), and the trailer axle(s), plus the total weight. For this reason, the scale consists of three platforms.

Due to the dimensions of the various RV combinations, it might be difficult to get the right axles positioned on the right platforms. You might have to move during the weighing process.

Some trucks that are over-length or that have a spread-axle trailer need to do this. That is another reason to park, look at the scale first, and then go inside to chat with the weighmaster.

But ideally, you want your front axle on the first platform, your rear axle(s) on the second platform, and anything you are towing on the third platform.

If the lengths just don’t work out, the weighmaster will give you instructions and have you move during the weighing process to position the axles on the platforms as needed. How-to weigh instructions can be found on their website.

When approaching the scale, make sure you have enough distance available to allow your vehicle combination to straighten out before reaching the scale.

Then, pull onto the platforms slowly and smoothly. Be sure to brake gently. It’s not good for the platforms to shake them by applying the brakes too suddenly.

Use your mirrors to check the position of your axles on the platforms and follow the instructions given by the weighmaster.

There is an intercom like those at a fast-food drive-through. He may ask for a truck number for your weigh ticket. You might just be able to say “RV” or give a few digits of your license plate number.

After weighing, park your rig and then go inside to get the weigh ticket.

Don’t block the scale by going inside while your rig is sitting there in the way.

CAT Scale offers a phone app also which might be an advantage if you plan to weigh very often.

Driving a Class A motorhome on Utah Scenic Byway 12 © Rex Vogel, all rights reserved

Other options to weigh my RV

Another option, rather than using a CAT scale at a busy truck stop, might be to visit a local grain facility to see if they allow weighing but not during the fall harvest season.

If you have a friend who is a farmer with their own scale, you have that as an option, also. This would allow you to disconnect the trailer if you want to know the separate weights of the towing vehicle and the trailer without any of the trailer weight being supported by the towing vehicle.

Some scales rather than having three platforms just have one narrow platform that can weigh only one axle at a time.

Some require the vehicle to be still; others can weigh while the vehicle is moving slowly across the platform. You might have to stop for a bit with each axle on the platform so each axle can be weighed separately before you move up to weigh the next axle.

The scale may be able to add up the weights or it may only provide the separate weights and you’ll have to do the math. The slow-moving scale might be the same: it will provide separate axle weights but it may or may not do the math.

An important point is to approach the scale from the proper direction.

Some scales are located so that an approach from only one direction is possible or feasible. Others are in the middle of the lot and could be approached from either direction.

Look for the word, ENTER on the overhead sign. Clearance? Well, all vehicles are limited to 13 feet 6 inches in height except for oversized loads and the sign has room to spare for a semi so there should be room to spare for your RV to fit.

Note that the option of an agricultural scale above may require you to both unhitch and reposition even to get the separate front and rear axle weights of the towing vehicle.

The agricultural facilities are not usually concerned with the individual axle weights. They are concerned with two weights: a full-grain truck and the same truck when it is empty. Thus, they often consist of only one long platform and cannot provide individual axle weights.

Driving a Class A motorhome on U.S. Highway 89 in northern Arizona © Rex Vogel, all rights reserved

What is four-corner weight?

It is important to note that truck stop scales can only weigh an entire axle. They cannot weigh the left side and right side separately. For this, you will have to find an RV dealer that has the equipment to weigh each tire separately.

The cost is higher but pales in comparison to the cost of a blowout if the axle is too heavy on one side even though it is within its weight rating limit.

Total axle weight is important but side-to-side balance is also important to avoid overloading one side of the axle.

Even though four-corner weight as it’s called is important, total axle weight is still important to know when four-corner weight cannot be determined.

Four-corner weight is also known as wheel position weight—the weight of each wheel on the vehicle.

If you are a member of Escapees RV Club (one of the RV memberships I recommend) you can use SmartWeigh to get this four-corner weight. According to Escapees, the SmartWeigh program provides critical RV weight safety and load management information in a highly accurate and usable format.

If you are involved in an accident, having the weigh ticket as proof of being within limits can be an important document to have. Be aware, though, of weight creep.

You know, you add this to a compartment, you add that, you modify, and before long, you no longer weigh what you weighed the last time you visited a scale.

Driving a motor coach on Newfound Gap Road in Great Smoky Mountains National Park, North Carolina © Rex Vogel, all rights reserved

Weight definitions

For those of you who really want to dig into this topic the generally accepted weight definitions are as follows:

  • Dry weight: Weight of the empty vehicle with no fluids or contents.
  • Curb weight: Weight of the vehicle parked at the curb ready to be driven usually including coolant, oil, and a full fuel tank.
  • GAWR: Gross Axle Weight Rating is the maximum amount of weight one individual axle can carry. In the case of a true tandem axle, sometimes each individual axle is given its own rating and sometimes the entire two-axle assembly is given a rating. RVs seldom have a true tandem axle (two axles connected to a single assembly which is in turn connected to the chassis). A trailer with two axles has two individual axles not a tandem axle assembly. A tag axle on a longer Class A is not the same as a tandem axle.
  • GVWR: Gross Vehicle Weight Rating is the maximum amount that the entire vehicle can weigh. This might be less than the sum of the GAWR values. A vehicle maker might have to specify a larger capacity axle for one reason or another (e.g., larger brakes) but perhaps the drive train is not meant for this much weight. Thus, the GVWR might be less than the sum of the individual GAWRs.
  • Towing capacity: Weight that a vehicle can tow. A tow vehicle might be able to TOW 10,000 pounds but perhaps it can CARRY only 500 of those pounds—the tongue weight—on its hitch assembly. The tongue weight must factor into the GVWR and will also affect the GAWR of the rear axle.
  • GCWR: Gross Combined Weight Rating is the total weight of the entire combination vehicle: the tow vehicle, the vehicle being towed, all fuel and water, all persons and luggage and equipment in the tow vehicle, and all water and possessions and camping gear in the towed vehicle. With a Class A, B, or C, this is the weight of the RV plus the weight of the towed car (and maybe a dolly or trailer) or boat or whatever else might be back there.
Driving a Class C motorhome in Utah Scenic Byway 12 © Rex Vogel, all rights reserved

Now that we have that squared away—where are you going to go? Here are a few suggestions:

Worth Pondering…

I’m still learning.

—Michelangelo