GMC 2002 Sierra - Manual (Page 286)

4-57
Q:
What is front axle reserve capacity, and how do
I calculate it?
A:
Front axle reserve capacity is the difference
between your front GAWR and the front axle
weight of your truck with full fuel and passengers.
Basically, it’s the amount of weight you can add to
your front axle before reaching your front GAWR.
The front axle reserve capacity for your vehicle can
be found in the lower right corner of the
Certification/Tire label, as shown.
United States Canada
In order to calculate the amount of weight any front
accessory, such as a snow plow, is adding to the
front axle, use the following formula:
(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