Hummer 2007 H3 Owner's Manual page 293

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.
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.
CAUTION:
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Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (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: Overloading your vehicle may cause
damage. Repairs would not be covered by
your warranty. Do not overload your vehicle.
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