Buick 2006 Rainier - Manual (Page 309)

Since tongue weight is usually at least 10 percent of
total loaded trailer weight, you can expect that the
largest trailer your vehicle can properly handle is
6,000 lbs (2 721 kg).
It is important that you make sure your vehicle does
not exceed any of its ratings — GCWR, GVWR,
RGAWR, Maximum Trailer Rating or Tongue Weight.
The only way to be sure you are not exceeding any
of these ratings is to weigh your vehicle and 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 Certification label at the rear edge of the driver’s
door or see Loading Your Vehicle on page 4-45 for more
information. Then be sure you don’t go over the GVW
limit for your vehicle, or the GAWR, including the weight
of the trailer tongue. If you use a weight distributing
hitch, make sure you don’t go over the rear axle
limit before you apply the weight distribution spring bars.
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.
Weight Distributing Hitches and Weight
Carrying Hitches
When using a weight-distributing hitch, the hitch must
be adjusted so the distance (A) remains the same both
before and after coupling the trailer to the tow vehicle.
If you use a step-bumper hitch, the bumper could
be damaged in sharp turns. Make sure there is ample
room when turning to avoid contact between the
trailer and the bumper.
(A) Body to Ground Distance, (B) Front of Vehicle
4-57