Chevrolet 2006 TrailBlazer EXT Owner's Manual page 337

Your vehicle may have an electronically controlled air
suspension system that automatically keeps your vehicle
level as you load and unload your vehicle. See
Electronically Controlled Air Suspension System on
page 4-58 for additional information.
Certification/Tire Label
A vehicle specific Certification/Tire label is found on the
rear edge of the driver's door. The label shows the
size of your vehicle's original tires and the inflation
pressures needed to obtain the gross weight capacity of
your vehicle.
This is called Gross Vehicle Weight Rating (GVWR).
The GVWR includes the weight of the vehicle, all
occupants, fuel, cargo, and trailer tongue weight,
if pulling a trailer.
The Certification/Tire label 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 centerline.
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.
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