Pontiac 2003 Bonneville Owner's Manual page 255

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. 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 4-34 for more information about your
vehicle's maximum load capacity.
A B
If you're using a weight-carrying hitch or a
weight-distributing hitch, the trailer tongue (A) should
weigh 10-15 percent of the total loaded trailer
weight (B).
After you've loaded your trailer, weigh the trailer and
then the tongue, separately, to see if the weights
are proper. If they aren't, you may be able to get them
right simply by moving some items around in the
trailer.
Total Weight on Your Vehicle's Tires
Be sure your vehicle's tires are inflated to the upper limit
for cold tires. You'll find these numbers on the
Tire-Loading Information label at the rear edge of the
driver's door or see Loading Your Vehicle on page 4-34.
Then be sure you don't go over the GVW limit for
your vehicle, including the weight of the trailer tongue.
Hitches
It's important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are
a few reasons why you'll need the right hitch. Here
are some rules to follow:
The rear bumper on your vehicle is not intended for
hitches. Do not attach rental hitches or other
bumper-type hitches to it. Use only a
frame-mounted hitch that does not attach to the
bumper.
4-38