Cadillac 2008 SRX Owner's Manual page 280

But let us 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.
4-46
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 will find these numbers on the
Certification/Tire label. See Loading Your Vehicle on
page 4-33. Then be sure you do not go over the GVW
limit for your vehicle, including the weight of the
trailer tongue.