GMC 2003 C4C042 Owner's Manual page 224

The GVWR includes the weight of the vehicle, all
occupants, fuel and cargo.
The GVW Rating label is provided by the final
manufacturer and should be on the door or door jamb.
It also tells you the maximum weights for the front and
rear axles, called Gross Axle Weight Rating (GAWR).
To find out the actual loads on your front and rear axles,
you need to go to a weigh station and weigh your
vehicle. Your dealer can help you with this. Be sure
to spread out your load equally on both sides of the
center line.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
And, if you do have a heavy load, you should spread
it out.
CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose control
and crash. Also, overloading can shorten the life
of your vehicle.
Using heavier suspension components to get added
durability might not change your weight ratings. Ask
your dealer to help you load your vehicle the right way.
NOTICE:
Your warranty does not cover parts or
components that fail because of overloading.
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