Pontiac 2004 Grand Am - Manual (Page 221)

If you are using a weight-carrying hitch, the trailer
tongue (A) should weigh 10–15 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.
Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are inflated to the upper limit
for cold tires. You will 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 4-35.
Then be sure you do not go over the GVW limit for
your vehicle, including the weight of the trailer tongue.
Hitches
It is 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.
• Will you have to make any holes in the body of
your vehicle when you install a trailer hitch? If
you do, then be sure to seal the holes later when
you remove the hitch. If you do not seal them,
deadly carbon monoxide (CO) from your exhaust
can get into your vehicle. See Engine Exhaust
on page 2-33. Dirt and water can, too.
4-43