"OVERWEIGHT!!!" "How can I be OVERWEIGHT?"
The scale master has just informed you that you are exceeding the "GAWR" on your rear axle and you cannot leave the scale until the condition is fixed.
The fellow you bought the camper from said it was designed for a half ton, but the Highway Patrol said you were swaying and escorted you to the scale.
Now you've stuck. Can't happen to you? Not if you take some precautions before you set out.
Dry weight, loaded weight, payload, GVWR, GAWR, GVW, GCWR, GCW, tare weight, curb weight, the list seems to go on and on. Basically you can save yourself the problem if you just take some simple steps before you buy a Recreational Vehicle or camper.
Every wheeled unit that is to be driven or towed is designed to have a gross vehicle weight rating (GVWR). That is the maximum it can legally weigh. In addition each axle has a maximum rating known as Gross Axle Weight Rating. Exceeding either of these ratings results in an overload condition resulting in safety and wear concerns.
How can the public protect themselves from inconvenience and danger? Simply ensure the carrying or towing vehicle is rated above the actual weight of the total package.
The manufacturers of trucks publish usually on the driver side doorpost, the GVWR and GAWR for the unit. On motorhomes and trailers it is found somewhere inside the unit. If you are about to buy a camper, load it up and weigh each truck axle separately. Don't forget to fill the fresh water tank. Add about 1,000 lbs for "Stuff" and you'll be safe.
Towing vehicle manufacturers also publish "Towing Guides" that give you a guideline for the engine, transmission, axle ratio and axle capacity Gross Combined Vehicle Rating (GCWR). Where GVWR is mainly concerned with CARRYING CAPACITY, GCWR is concerned with towing and stopping the load. Recreational Dealers also publish the DRY weight of the campers, trailers and usually motorhomes that they sell and have access to the truck specialists at the local truck dealers. This is a good reason to buy from an authorized franchised dealer. Be sure that you add the water capacity at 10 lb per gallon and of course the 1,000 lbs of "stuff". More if it's one of those big fifth wheels.
If you do buy a camper or trailer privately take it to a scale and weight it. Be sure it is full of water when you do. If the weight is close to the GVWR of your truck or the GCWR of your tow unit you might want to invest in a professional weight analysis. Your RV dealer or a local heavy truck dealer should be able to steer you in the right direction for this service.
While this is a bit of work it can save you a lot of aggravation later.

DEFINITIONS:
GVWR: Gross vehicle weight rating. The maximum allowable weight of the vehicle and all that it is carrying.
GVW: Gross vehicle weight. What the vehicle weighs at a given moment in time.
GAWR: Gross axle weight rating. Maximum weight an axle is designed to carry as equipped.
GCWR: Gross combined weight rating. Maximum weight of the towing and towed vehicles that is permitted for this unit.
GCW: Gross combined weight. What the towed and towing vehicle weigh at a given moment.
Curb Weight: The weight of a vehicle with all fluids on board but with no payload.
Payload: Passengers, extra equipment and cargo that a vehicle carries. The maximum payload is the difference between the tare weight and the GVWR.
Tare Weight: The weight without cargo of a vehicle ready to be loaded with payload.

While this is a quick overview of the subject, we can if there is an interest in it, provide future articles on specing, weight distribution and a trailer guide.
Allan B Anderson
Dams Ford Truck Sales
Surrey BC