(A) Temporary Use Only:The compact spare tire or
temporary use tire has a tread life of approximately
3,000 miles (5 000 km) and should not be driven
at speeds over 65 mph (105 km/h). The compact spare
tire is for emergency use when a regular road tire
has lost air and gone at. If your vehicle has a compact
spare tire, seeCompact Spare Tire on page 5-84
andIf a Tire Goes Flat on page 5-67.
(B) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.(C) Tire Identi cation Number (TIN):The letters and
numbers following the DOT (Department of
Transportation) code is the Tire Identi cation Number
(TIN). The TIN shows the manufacturer and plant code,
tire size, and date the tire was manufactured. The
TIN is molded onto both sides of the tire, although only
one side may have the date of manufacture.
(D) Maximum Cold In ation Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load.
(E) Tire In ation:The temporary use tire or compact
spare tire should be in ated to 60 psi (420 kPa).
For more information on tire pressure and in ation see
In ation - Tire Pressure on page 5-57.
(F) Tire Size:A combination of letters and numbers
de ne a tire’s width, height, aspect ratio, construction
type and service description. The letter T as the
rst character in the tire size means the tire is for
temporary use only.
(G) TPC Spec (Tire Performance Criteria
Speci cation):Original equipment tires designed to
GM’s speci c tire performance criteria have a TPC
speci cation code molded onto the sidewall. GM’s TPC
speci cations meet or exceed all federal safety
guidelines. Compact Spare Tire Example
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Tire Size
The following illustration shows an example of a typical
passenger vehicle tire size.
(A) Passenger (P-Metric) Tire:The United States
version of a metric tire sizing system. The letter P as the
rst 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 60, as shown in item C of
the illustration, it would mean that the tire’s sidewall is
60 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 range and speed rating of the tire. The load
index represents the load carry capacity a tire is certi ed
to carry. The load index can range from 1 to 279. The
speed rating is the maximum speed a tire is certi ed
to carry a load. Speed ratings range from A to Z.
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