Chevrolet 2000 Tahoe Owner's Manual page 250

Front Axle Reserve Capacity
This is the difference between your front GAWR and
the front axle weight of your truck with full fuel and
passengers. It is the amount of weight you can add to
your front axle before reaching your front GAWR.
In order to calculate the amount of weight any
front accessory is adding to the front axle, use the
following formula.
The front axle reserve
capacity for your vehicle
can be found in the lower
right hand corner of the
tire/certification label, as
shown in this example.
(W x (A+W.B.)) / W.B.= Weight the accessory is adding
to the front axle
Where: W= Weight of added accessory
A= Distance that the accessory is
in front of the front axle
W.B.= Vehicle Wheelbase
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