Jeep 2010 Grand Cherokee Owner's Manual page 320

320 STARTING AND OPERATING
WARNING!
It is important that you do not exceed the maximum
front or rear GAWR. A dangerous driving condition
can result if either rating is exceeded. You could lose
control of the vehicle and have an accident.
Trailer Tongue Weight (TW)
The TW is the downward force exerted on the hitch ball
by the trailer. In most cases it should not be less than 10%
or more than 15% of the trailer load. You must consider
this as part of the load on your vehicle.
Frontal Area
The frontal area is the maximum height and maximum
width of the front of a trailer.
Weight-Carrying Hitch
A weight-carrying hitch supports the trailer tongue
weight, just as if it were luggage located at a hitch ball or
some other connecting point of the vehicle. These kind of
hitches are the most popular on the market today and
they are commonly used to tow small- and medium-
sized trailers.
Weight-Distributing Hitch
A weight-distributing hitch system works by applying
leverage through spring (load) bars. They are typically
used for heavier loads, to distribute trailer tongue weight
to the tow vehicle's front axle and the trailer axle(s).
When used in accordance with the manufacturers' direc-
tions, it provides for a more level ride, offering more
consistent steering and brake control, thereby enhancing
towing safety. The addition of a friction/hydraulic sway
control also dampens sway caused by traffic and cross-
winds, and contributes positively to tow vehicle and
trailer stability. Trailer sway control and a weight-
distributing (load equalizing) hitch are recommended for
heavier trailer tongue weights (TW) and may be required