What GIJOE says is correct, basically you should start by reading your door sticker........here is something I copied:
GM says:
The CWR is the maximum weight of the load your vehicle can carry. It doesn't include the weight of the people inside. But, you can figure about 150 pounds for each seat.
The total cargo load must not be more than your vehicle's CWR.
ALSO......from my owner’s manual (GM):
After you’ve loaded your vehicle and camper, drive to a weigh station and weigh on the front and rear wheels separately. This will tell you the loads on your axles. The loads on the front and rear axles shouldn’t be more than either of the GAWRs. The total of the axle loads should not be more than the GVWR.
Open your vehicle’s driver’s door and look at the Certificate/Tire label to find out your GAWR and GVWR.
If you’ve gone over your weight rating, move or take out some things until all the weights fall below the ratings. Of course, you should always tie down any loose items when you load your vehicle or camper.
If you want more information on curb weights, cargo weights, cargo weight ratings and the correct center of gravity zone for your vehicle, your dealer can help you. Just ask for a copy of “Consumer Information, Truck-Camper Loading.”
Also, there is no set answer as to how much your vehicle can tow safely, GM says:
It depends on how you plan to use your rig. For example, speed, altitude, road grades, outside temperature and how much your vehicle is used to pull a trailer are all important. And, it can depend on any special equipment that you have on your vehicle.
You can ask your dealer for our trailering information or advice, or you can write at the address listed in your Warranty and Owner Assistance Information Booklet.
But, then again GM also says:
If your vehicle comes with the trailering Package, there is also a load rating which includes the weight of the vehicle and the trailer it tows. This rating is called the Gross Combination Weight Rating (GCWR).
When you weigh your trailer, be sure to include the weight of everything you put in it. And, remember to figure the weight of the people inside as part of your total.
Your dealer can help you determine your GCWR.
CWR = Cargo Weight Rating
GVWR = Gross Vehicle Weight Rating
GCWR = Gross Combination Weight Rating
GAWR = Gross Axle Weight Rating
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Aloha,Mark
PS......BEWARE OF ALL THIS.......cause, IF you exceed your ratings and get into an accident......it's almost a slam dunk, for a lawyer looking for liability.