Saab 2006 9-7X - Manual (Page 275)

The weight at the rear axle could be 850 lbs
(386 kg) X 1.5 = 1,275 lbs (578 kg). Since the
rear axle already weighs 2,700 lbs (1 225 kg), adding
1,275 lbs (578 kg) brings the total to 3,975 lbs (1 803 kg).
This is very close to, but within the limit for RGAWR
as well. The vehicle is set to trailer up to 8,500 lbs
(3 856 kg).
But let’s say your specific vehicle is equipped with some
of the latest options and you have a front seat passenger
and two rear seat passengers with some luggage and
gear in the vehicle as well. You may add 300 lbs (136 kg)
to the front axle weight and 400 lbs (181 kg) to the rear
axle weight. Your vehicle now weighs:
Weight is still below 7,200 lbs (3 266 kg) and you may
think that you should subtract 700 additional pounds
(318 kg) from your trailering capacity to stay within
GCWR limits. Your maximum trailer would only be
7,800 lbs (3 538 kg). You may go further and think you
must limit tongue weight to less than 1,000 lbs (454 kg)
to avoid exceeding GVWR.
But, you must still consider the effect on the rear axle.
Because your rear axle now weighs 3,100 lbs (1 406 kg),
you can only put 900 lbs (408 kg) on the rear axle without
exceeding RGAWR. The effect of tongue weight is about
1.5 times the actual weight. Dividing the 900 lbs (408 kg)
by 1.5 leaves you with being able to handle only
600 lbs (272 kg) of tongue weight. 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 4-33 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.
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