This is a lot of fun right… going where you want when you want… there’s nothing
else like it.
Before you load up the RV and hit the highway - there are a few terms, definitions and even
some math you need to be aware of to ensure you have a safe trip.
So grab your RV Dictionaries… and your calculators because we are going to dive into everything
you need to know about weights… towing and capacity.
Let’s start with Curb Weight This is the weight of the motorhome with a
full tank of fuel - be it gas or Diesel.
Curb weight does not include you cargo, your water, propane, or even passengers.
Unloaded Vehicle Weight or (U-V-W) is similar to curb weight, but for a motorhome, U-V-W
is the Curb Weight of the motorhome WITH a full tank of L-P.
Let’s talk about Cargo Weight This is ALL the weight, every pound, added
to the Curb Weight.
This DOES includes cargo, water, propane, passengers, and any aftermarket optional equipment.
Take note here, when towing, trailer tongue load is also part of your Cargo Weight and
we will talk about towing here soon.
The Occupant and Cargo Carrying Capacity or (O-C-C-C) is this number printed on the yellow
weight label.
You can find this on the entry door of the motorhome.
This is important information.
This little sticker lets you know how much weight you can add to your motorhome.
Simply put, the OCCC is determined by subtracting the U-V-W of the motorhome from the GVWR of
the chassis.
You may have heard the term Gross Vehicle Weight Rating or (GVWR).
This is the MAXIMUM allowable weight of a fully-loaded motorhome.
This number – along with other weight limits, as well as tire, rim size and inflation pressure
data – is shown on the vehicle’s Safety Compliance Certification Label.
Here’s an example of what to look for, you’ll find this located near the driver seat
Your Gross Vehicle Weight (GVW) Is The Curb Weight - plus actual cargo, water, LP, and
passengers.
It’s crucial to understand G-V-W is not a limit, it’s not a specification... it
is the actual weight you have when the motorhome is placed on a scale.
This is simply how much your motorhome weighs as it travels down the road.
Important note…
The G-V-W must never exceed the G-V-W-R.
So your bays are packed and now you’re ready to connect something to your hitch…
You can’t just hook and go… there’s a lot to this - so let’s get into some towing
terminology and look at the proper way to roll down the road.
You’ve seen these... this is a trailer... you have a few variations
It’s unpowered, used to haul all your goodies and designed to be pulled behind the motorhome.
The typical trailer carries a portion of its weight on the trailer axle, and the rest of
its weight is carried, through the trailer tongue, by the motorhome hitch.
That leads us to Tongue Load or Tongue Weight This is the amount of the trailer’s weight
that presses down on the trailer hitch.
Too much tongue load can cause damage to your suspension, drivetrain and frame.
It works the other way too.
Not enough tongue load can cause instability.
You can find the maximum gross tongue weight listed on the motorhome hitch.
You do need be sure the addition of tongue weight does not exceed the key towing weight
limits - that’s your GVWR and Rear GAWR.
You can find GVWR and GAWR on the motorhomes Safety Compliance Certification Label.
If you are above either of these limits - your safest bet is to go with a smaller trailer.
Here’s something else to think about… the way you have the trailer loaded and if
it is going to affect your tongue weight.
If you have too much tongue weight, shift some of the cargo to the rear inside the trailer.
When it comes to hitches…
Do not use a Weight Distributing (or Load Leveling) hitch with your motorhome.
It’s not capable of transferring any useful amount of weight from the rear axle to the
front axle, or limiting up and down hitch movement and you could end up damaging the
hitch, the receiver, the rear overhang of the motorhome frame, or the trailer frame
itself.
How about hooking up a Toad?
(OR a Dinghy vehicle).
Toad is a slang term for “towed automobile” – typically a car or SUV you pull behind
the motorhome.
It involves attaching a tow bar to the vehicle to roll along behind the motorhome on its
own four tires (you may have heard it called four-down towing or flat towing).
Unlike a trailer, a Toad places very little tongue load onto the motorhome hitch.
But, only certain vehicles can be used as a Toad behind a motorhome so you need to check
the car’s owner manual for all the details and specifications.
The Maximum Loaded Trailer Weight (or Towing Capacity) is the highest possible weight of
a fully loaded trailer, or Toad, the motorhome can tow - based on a minimally loaded motorhome
GVW.
You may want to hit the nearest scale for our next few items.
Gross Axle Weight (G-A-W) is the total weight placed on each axle (both front and rear.)
To determine the Gross Axle Weights for your motorhome and vehicle or trailer combination,
take your loaded RV and tow vehicle or trailer to a scale.
With the trailer attached, place the front wheels of the motorhome on the scale to get
the front G-A-W.
For rear G-A-W, weigh the motorhome with the trailer attached, but with only the four wheels
of the motorhome on the scale.
Subtracting front G-A-W from that amount gives you rear G-A-W.
Add an R to the end and now you have (GAWR) – your Gross Axle Weight Rating
This is the maximum weight to be carried by a single axle.
On a motorhome, the rear axle GAWR is larger than the front axle GAWR.
These numbers are also shown on the Safety Compliance Certification Label.
The total load on each axle, GAW, must never exceed its GAWR.
The Gross Combination Weight (G-C-W) is the weight of the loaded motorhome (GVW) plus
the weight of the fully loaded trailer or toad.
It is the actual weight you get when the motorhome and trailer combination are weighed together
on a scale.
The Gross Combination Weight Rating (GCWR) is the maximum allowable weight of the motorhome
and the loaded trailer, or toad, that the motorhome can handle without the risk of being
damaged.
GCWR is a value determined by the chassis manufacturer, and is dependent on the GVWR,
engine size, and axle ratio of the motorhome chassis.
GCWR weight ratings are found in the Towing Guide or Spec Sheets, published by the chassis
manufacturer.
GCWR information for current model year motorhomes can also be found on the SPECS page of the
Thor Motor Coach website www.thormotorcoach.com.
Here’s an important note: The motorhome’s brake system is rated for operation at the
GVWR, not GCWR.
A supplemental braking system should be used for safe control of towed vehicles and for
trailers weighing more than 1,500 pounds when loaded.
The measured GCW must never exceed GCWR.
So are you ready for a little math?
Here’s what you need to add or subtract to determine some Important Capacities
For your Gross Vehicle Weight (GVW) = That’s Curb Weight + Cargo Weight + Water
Weight + LP Weight + Passenger Weight + Tongue Weight.
REMEMBER - GVW must not exceed GVWR.
To figure out your Gross Combination Weight (GCW) =
That’s GVW + Trailer Weight (or Toad Weight).
And remember GCW must not exceed GCWR.
TO get your Towing Capacity = It’s simply GCWR – GVW.
Be sure to also follow the maximum Gross Trailer Weight Rating that is shown on the motorhome
hitch itself, your towing capacity may be limited by the hitch rating).
And one last Important note: When towing, remember to always stay within your GCWR,
GVWR, GAWR’s and hitch ratings to safely tow a trailer or toad with your motorhome.
Now that you have all the info, load up, go hit the road and make some memories.
For more owners resources visit thormotorcoach.com