When we’re talking about a house on wheels, it’s important to understand all the different terms used to talk about weight; what they mean, how to use them, and why they matter.
First things first, here’s some terms you need to know:
1) GVWR: Gross Vehicle Weight Rating
This is the total amount of weight your vehicle is designed to carry, and going over this amount is a recipe for disaster.
This applies to any single vehicle, so you’ll have one for your truck (or tow vehicle), another for your trailer, or one for your motorhome.
2) GCWR: Gross Combined Weight Rating
This is the total amount of weight your vehicle can weigh in combination with another vehicle, such as when you’re towing a trailer. If you’re towing a trailer, then you’d want to make sure your GVWR of your truck, plus the GVWR of your trailer, is NOT more than the GCWR for your tow vehicle.
3) GAWR: Gross Axle Weight Rating
This is the total amount of weight a single axle can support. Not as common, but worth noting here.
4) Towing Capacity
This is the maximum towing capacity for your vehicle, or the maximum amount of weight it can tow.
5) Curb (dry) weight
Curb weight is how much your vehicle weighs dry and empty (sitting on the curb). Think of this as how much your vehicle weighs without stuff, people, fuel, water, luggage, so on and on and on…
6) Tongue Weight
On your tow vehicle, this is how much weight you can put on the tongue of the vehicle, which is different than the total weight of the trailer.
On your trailer, this is how much weight should be on the tongue of the trailer, which is different than the weight placed on the wheels.
Okay, now that we have some terms down, let’s add one more section, weights per gallon:
1) Water weighs 8.3 lbs per gallon at 62°F, and
2) Gasoline weighs 6.3 lbs per gallon, and,
3) Propane weighs 4.2 lbs per gallon, and,
4) These weights vary with temperature because the mass changes with density.
The reason these numbers matter is because vehicles (all vehicles) are designed with specifications, and so long as they are used inside those specifications, they will operate as intended, as tested, and as certified. Anytime you operate a vehicle outside of its specifications, you run the risk of causing damage to the vehicle, losing control of the vehicle, or other troubles.
Read on in the following posts to learn more about Weights and Measures.