GMC 2008 Savana Van Owner's Manual page 296

(G) Single Tire Maximum Load
that can be carried and the maximum pressure
needed to support that load when used as a
single. For information on recommended tire
pressure see Inflation - Tire Pressure on page 5-60
and Loading Your Vehicle on page 4-20.
Tire Size
The following examples show the different parts of
a tire size.
Passenger (P-Metric) Tire
Light Truck (LT-Metric) Tire
5-56
Maximum load
:
(A) Passenger (P-Metric) Tire
version of a metric tire sizing system. The letter P
as the first character in the tire size means a
passenger vehicle tire engineered to standards
set by the U.S. Tire and Rim Association.
(A) Light Truck (LT-Metric) Tire
States version of a metric tire sizing system. The
letters LT as the first two characters in the tire
size means a light truck tire engineered to
standards set by the U.S. Tire and Rim
Association.
(B) Tire Width The three-digit number indicates
:
the tire section width in millimeters from sidewall
to sidewall.
(C) Aspect Ratio A two-digit number that
:
indicates the tire height-to-width measurements.
For example, if the tire size aspect ratio is 75, as
shown in item C of the light truck (LT-Metric) tire
illustration, it would mean that the tire's sidewall is
75 percent as high as it is wide.
(D) Construction Code
indicate the type of ply construction in the tire.
The letter R means radial ply construction; the
letter D means diagonal or bias ply construction;
and the letter B means belted-bias ply construction.
The United States
:
The United
:
A letter code is used to
: