Chevrolet 2007 TrailBlazer Owner's Manua page 360

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).
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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.
Similar appearing vehicles may have different
GVWRs and capacity weights. Please note your
vehicle's Certification/Tire label or consult
your dealer for additional details.