CHEVROLET 2009 Suburban - Manual (Page 465)

(F) Tire Ply Material : The type of cord and number
of plies in the sidewall and under the tread.
(G) Single Tire Maximum Load : 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 5-70 and Loading the Vehicle on page 4-33.
Tire Size
The following examples show the different parts of
a tire size.
(A) Passenger (P-Metric) Tire : The United States
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.
(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 tire illustration, it would
mean that the tire’s sidewall is 75 percent as high
as it is wide.
(D) Construction Code : A letter code is used to
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.
(E) Rim Diameter : Diameter of the wheel in
inches.
(F) Service Description : These characters
represent the load index and speed rating of the
tire. The load index represents the load carry
capacity a tire is certified to carry. The speed
rating is the maximum speed a tire is certified to
carry a load.
Passenger (P-Metric) Tire
5-65