Pontiac 2004 Bonneville - Manual (Page 271)

Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important weight
to measure because it affects the total or gross weight of
your vehicle. The Gross Vehicle Weight (GVW) includes
the curb weight of the vehicle, any cargo you may carry in
it, and the people who will be riding in the vehicle. If you
have a lot of options, equipment, passengers, or cargo in
your vehicle, it will reduce the tongue weight your vehicle
can carry, which will also reduce the trailer weight your
vehicle can tow. And if you tow a trailer, you must add the
tongue load to the GVW because your vehicle will be
carrying that weight, too. See Loading Your Vehicle on
page 4-33 for more information about your vehicle’s
maximum load capacity.
If you are using a weight-carrying hitch, the trailer
tongue (A) should weigh 10 to 15 percent of the total
loaded trailer weight (B).
After you have loaded your trailer, weigh the trailer and
then the tongue, separately, to see if the weights are
proper. If they are not, you may be able to get them right
simply by moving some items around in the trailer.
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