Chevrolet 2004 Impala Owner's Manual page 255

Certification Label
The Certification label is found on the rear edge of the
driver's door. It tells you the gross weight capacity
of your vehicle, called the Gross Vehicle Weight Rating
(GVWR). The GVWR includes the weight of the
vehicle, all occupants, fuel and cargo. Never exceed the
GVWR for your vehicle or the Gross Axle Weight
Rating (GAWR) for either the front or rear axle.
If you do have a heavy load, spread it out. Don't carry
more than 167 pounds (75 kg) in your trunk.
CAUTION:
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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.
Notice: Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
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