width CHEVROLET SONIC 2017 2.G Owners Manual

Chevrolet Sonic Owner Manual (GMNA-Localizing-U.S./Canada-10122660) -2017 - crc - 5/13/16
Vehicle Care 251
Passenger (P-Metric) Tire Example
(1) Tire Size:The tire size is a
combination of letters and
numbers used to define a
particular tire's width, height,
aspect ratio, construction type,
and service description. See the
“Tire Size”illustration later in this
section.
(2) TPC Spec (Tire
Performance Criteria
Specification):Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet or
exceed all federal safety
guidelines.
(3) DOT (Department of
Transportation):The
Department of Transportation
(DOT) code indicates that the
tire is in compliance with the
U.S. Department of
Transportation Motor Vehicle
Safety Standards.
DOT Tire Date of
Manufacture:The last four
digits of the TIN indicate the tire
manufactured date. The first two
digits represent the week (01–
52) and the last two digits, the
year. For example, the third
week of the year 2010 would
have a four-digit DOT date
of 0310.
(4) Tire Identification Number
(TIN):The letters and numbers
following the DOT (Department
of Transportation) code are the
Tire Identification 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.
(5) Tire Ply Material:The type
of cord and number of plies in
the sidewall and under the tread.
(6) Uniform Tire Quality
Grading (UTQG):Tire
manufacturers are required to
grade tires based on three
performance factors: treadwear,
traction, and temperature
resistance. For more information
seeUniform Tire Quality
Grading0264.
(7) Maximum Cold Inflation
Load Limit:Maximum load that
can be carried and the
maximum pressure needed to
support that load.

Chevrolet Sonic Owner Manual (GMNA-Localizing-U.S./Canada-10122660) -2017 - crc - 5/13/16
252 Vehicle Care
Compact Spare Tire Example
(1) Tire Ply Material:The type
of cord and number of plies in
the sidewall and under the tread.
(2) Temporary Use Only:The
compact spare tire or temporary
use tire should not be driven at
speeds over 80 km/h (50 mph).
The compact spare tire is for
emergency use when a regular
road tire has lost air and gone
flat. If the vehicle has a compact
spare tire, seeCompact Spare
Tire0274andIf a Tire Goes
Flat0267.
(3) Tire Identification Number
(TIN):The letters and numbers
following the DOT (Department
of Transportation) code are the
Tire Identification 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.
(4) Maximum Cold Inflation
Load Limit:Maximum load that
can be carried and the
maximum pressure needed to
support that load.
(5) Tire Inflation:The
temporary use tire or compact
spare tire should be inflated to
420 kPa (60 psi). For more
information on tire pressure and
inflation seeTire
Pressure0256.
(6) Tire Size:Acombinationof
letters and numbers define a
tire's width, height, aspect ratio,
construction type, and service
description. The letter T as the
first character in the tire size
means the tire is for temporary
use only.
(7) TPC Spec (Tire
Performance Criteria
Specification):Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet or
exceed all federal safety
guidelines.
Tire Designations
Tire Size
The following is an example of a
typical passenger vehicle
tire size.

Chevrolet Sonic Owner Manual (GMNA-Localizing-U.S./Canada-10122660) -2017 - crc - 5/13/16
Vehicle Care 253
(1) 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.
(2) Tire Width:The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(3) Aspect Ratio:Atwo-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 60, as shown in
item 3 of the illustration, it would
mean that the tire's sidewall is
60 percent as high as it is wide.
(4) Construction Code:Aletter
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.
(5) Rim Diameter:Diameter of
the wheel in inches.
(6) Service Description:These
characters represent the load
index and speed rating of the
tire. The load index represents
the load carrying capacity a tire
is certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch of
the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight:The
combined weight of optional
accessories. Some examples of
optional accessories are
automatic transmission, power
windows, power seats, and air
conditioning.
Aspect Ratio:The relationship
of a tire's height to its width.
Belt:Arubbercoatedlayerof
cords between the plies and the
tread. Cords may be made from
steel or other reinforcing
materials.
Bead:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.
Bias Ply Tire:Apneumatictire
in which the plies are laid at
alternate angles less than
90 degrees to the centerline of
the tread.

Chevrolet Sonic Owner Manual (GMNA-Localizing-U.S./Canada-10122660) -2017 - crc - 5/13/16
Vehicle Care 265
most passenger car tires. The
Uniform Tire Quality Grading
(UTQG) system does not apply
to deep tread, winter tires,
compact spare tires, tires with
nominal rim diameters of
10 to 12 inches (25 to 30 cm),
or to some limited-production
tires.
While the tires available on
General Motors passenger cars
and light trucks may vary with
respect to these grades, they
must also conform to federal
safety requirements and
additional General Motors Tire
Performance Criteria (TPC)
standards.
Quality grades can be found
where applicable on the tire
sidewall between tread shoulder
and maximum section width. For
example:
Treadwear 200 Traction AATemperature A
All Passenger Car Tires Must
Conform to Federal Safety
Requirements In Addition To
These Grades.
Treadwear
The treadwear grade is a
comparative rating based on the
wear rate of the tire when tested
under controlled conditions on a
specified government test
course. For example, a tire
graded 150 would wear one and
one-half (1Ω) times as well on
the government course as a tire
graded 100. The relative
performance of tires depends
upon the actual conditions of
their use, however, and may
depart significantly from the
norm due to variations in driving
habits, service practices and
differences in road
characteristics and climate.
Traction
The traction grades, from
highest to lowest, are AA, A, B,
and C. Those grades represent
the tire's ability to stop on wet
pavement as measured under
controlled conditions on
specified government test
surfaces of asphalt and
concrete. A tire marked C may
have poor traction performance.
Warning: The traction grade
assigned to this tire is based on
straight-ahead braking traction
tests, and does not include
acceleration, cornering,
hydroplaning, or peak traction
characteristics.
Temperature
The temperature grades are A
(the highest), B, and C,
representing the tire's resistance
to the generation of heat and its
ability to dissipate heat when
tested under controlled
conditions on a specified indoor

Chevrolet Sonic Owner Manual (GMNA-Localizing-U.S./Canada-10122660) -2017 - crc - 5/13/16
266 Vehicle Care
laboratory test wheel. Sustained
high temperature can cause the
material of the tire to degenerate
and reduce tire life, and
excessive temperature can lead
to sudden tire failure. The grade
Ccorrespondstoalevelof
performance which all
passenger car tires must meet
under the Federal Motor Safety
Standard No. 109. Grades B and
Arepresenthigherlevelsof
performance on the laboratory
test wheel than the minimum
required by law. Warning: The
temperature grade for this tire is
established for a tire that is
properly inflated and not
overloaded. Excessive speed,
underinflation, or excessive
loading, either separately or in
combination, can cause heat
buildup and possible tire failure.
Wheel Alignment and Tire
Balance
The tires and wheels were alignedand balanced at the factory toprovide the longest tire life and bestoverall performance. Adjustments towheel alignment and tire balancingare not necessary on a regularbasis. Consider an alignment checkif there is unusual tire wear or thevehicle is significantly pulling to oneside or the other. Some slight pull tothe left or right, depending on thecrown of the road and/or other roadsurface variations such as troughsor ruts, is normal. If the vehicle isvibrating when driving on a smoothroad, the tires and wheels may needto be rebalanced. See your dealerfor proper diagnosis.
Wheel Replacement
Replace any wheel that is bent,cracked, or badly rusted orcorroded. If wheel nuts keep comingloose, the wheel, wheel bolts, andwheel nuts should be replaced.If the wheel leaks air, replace it.
Some aluminum wheels can berepaired. See your dealer if any ofthese conditions exist.
Yo u r d e a l e r w i l l k n o w t h e k i n d o fwheel that is needed.
Each new wheel should have thesame load-carrying capacity,diameter, width, offset, and bemounted the same way as the one itreplaces.
Replace wheels, wheel bolts, wheelnuts, or Tire Pressure MonitorSystem (TPMS) sensors with newGM original equipment parts.
{Warning
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts can be dangerous. It could
affect the braking and handling of
the vehicle. Tires can lose air,
and cause loss of control, causing
acrash.Alwaysusethecorrect
wheel, wheel bolts, and wheel
nuts for replacement.