Buick REGAL 1997 Manual page 231

Three important considerations have to do with weight:
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the weight of the trailer,
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the weight of the trailer tongue
and the total weight on your vehicle's tires.
Weight of the Trailer
How heavy can a trailer safely be?
It should never weigh more than 1,000 lbs. (450 kg). But
even that can be too heavy.
It depends on how you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to pull a
trailer are all important. And, it can also depend on any
special equipment that you have on your vehicle.
You can ask your dealer for our trailering information or
advice, or you can write us at:
Buick Motor Division
Customer Relations Center
902 E. Hamilton Avenue
Flint, MI 48550
In Canada, write to:
General Motors of Canada Limited
Customer Communication Centre
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important
weight to measure because it affects the total capacity
weight of your vehicle. The capacity weight includes the
curb weight of the vehicle, any cargo you may carry in
it,
and the people who will be riding in the vehicle. And
if you will tow a trailer, you must subtract the tongue
load from your vehicle's capacity weight because your
vehicle will be carrying that weight, too. See "Loading
Your Vehicle" in the Index for more information about
your vehicle's maximum load capacity.
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