Pontiac Grand Prix 2007 Owner's Manual page 332

When using a weight-carrying hitch or a
weight-distributing hitch, the trailer tongue (A)
should weigh 10 to 15 percent of the total loaded
trailer weight (B).
After the trailer is loaded, weigh the trailer and then
the tongue, separately, to see if the weights are
proper. The correct weight could be achieved
simply by moving some items around in the trailer.
Total Weight on Your Vehicle's Tires
Be sure the vehicle's tires are inflated to the upper
limit for cold tires. These numbers can be found
on the Tire and Loading Information label,
that is located on the driver's side center B-pillar.
332
See Loading Your Vehicle on page 322. Be sure
not to go over the GVW limit for the vehicle, or the
GAWR, including the weight of the trailer tongue.
If a weight distribution hitch is used, make sure not
to go over the rear axle limit before applying the
weight distribution spring bars.
Hitches
It is important to have the correct hitch equipment.
Crosswinds, large trucks going by, and rough
roads are a few reasons why the correct hitch
is needed. Here are some rules to follow:
•
The rear bumper on the 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.
•
If any holes need to be made in the body of the
vehicle to install a trailer hitch, then be sure to
seal the holes later when the hitch is removed.
If the holes are not sealed, deadly carbon
monoxide (CO) from the exhaust can get into
the vehicle. See Engine Exhaust on page 122.
Dirt and water can, too.