width CADILLAC CT4 2023 Owners Manual

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 417
tires be installed on the
vehicle if frequent driving at
temperatures below
approximately 5 °C (40 °F) or
on ice or snow covered roads
is expected. See Winter Tires
0414.
Caution
High performance summer
tires have rubber
compounds that lose
flexibility and may develop
surface cracks in the tread
area at temperatures below
−7 °C (20 °F). Always store
high performance summer
tires indoors and at
temperatures above −7 °C
(20 °F) when not in use. If the
tires have been subjected to
−7 °C (20 °F) or less, let them
warm up in a heated space
to at least 5 °C (40 °F) for
24 hours or more before
being installed or driving a
vehicle on which they are
installed. Do not apply heat
(Continued)
Caution (Continued)
or blow heated air directly
on the tires. Always inspect
tires before use. See Tire
Inspection0429.
Tire Sidewall Labeling
Useful information about a
tire is molded into its
sidewall. The example
shows a typical passenger
tire sidewall.
Passenger 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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 419
(2) Tire Width:The 3-digit
number indicates the tire
section width in millimeters
from sidewall to sidewall.
(3) Aspect Ratio
:A 2-digit
number that indicates the
tire height-to-width
measurements. For
example, if the tire size
aspect ratio is 75, as
shown in item (3) of the
illustration, it would mean
that the tire's sidewall is
75 percent as high as it
is wide.
(4) 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.
(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).
Aspect Ratio
:The
relationship of a tire's
height to its width. Belt
:A rubber coated layer
of cords that is located
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
:A pneumatic
tire in which the plies are
laid at alternate angles less
than 90 degrees to the
centerline of the tread.
Cold Tire Pressure
:The
amount of air pressure in a
tire, measured in kPa
(kilopascal) or psi (pounds
per square inch) before a
tire has built up heat from
driving. See Tire Pressure
0 422.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
434 Vehicle Care
{Warning
If different sized wheels are
used, there may not be an
acceptable level of
performance and safety if
tires not recommended for
those wheels are selected.
This increases the chance of
a crash and serious injury.
Only use GM specific wheel
and tire systems developed
for the vehicle, and have
them properly installed by a
GM certified technician.
See Buying New Tires 0432
and
Accessories and Modifications
0 370.
Uniform Tire Quality
Grading
The following information
relates to the system
developed by the United
States National Highway
Traffic Safety Administration (NHTSA),
which grades tires by
treadwear, traction, and
temperature performance.
This applies only to
vehicles sold in the United
States. The grades are
molded on the sidewalls of
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 AA
Temperature 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 (1½) times as

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
436 Vehicle Care
balancing are not necessary
on a regular basis. Consider an
alignment check if there is
unusual tire wear or the
vehicle is significantly pulling
to one side or the other. Some
slight pull to the left or right,
depending on the crown of the
road and/or other road
surface variations such as
troughs or ruts, is normal.
If the vehicle is vibrating when
driving on a smooth road, the
tires and wheels may need to
be rebalanced. See your
dealer for proper diagnosis.
Wheel Replacement
Replace any wheel that is
bent, cracked, or badly rusted
or corroded. If wheel nuts
keep coming loose, the wheel,
wheel bolts, and wheel nuts
should be replaced. If the
wheel leaks air, replace it.
Some aluminum wheels can be
repaired. See your dealer if
any of these conditions exist.
Your dealer will know the kind
of wheel that is needed.Each new wheel should have
the same load-carrying
capacity, diameter, width,
offset, and be mounted the
same way as the one it
replaces.
Replace wheels, wheel bolts,
wheel nuts, or Tire Pressure
Monitor System (TPMS)
sensors with new GM 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,
resulting in a crash. Always
use the correct wheel, wheel
bolts, and wheel nuts for
replacement.
{Warning
Replacing a wheel with a
used one is dangerous. How
it has been used or how far
it has been driven may be
unknown. It could fail
suddenly and cause a crash.
When replacing wheels, use
a new GM original
equipment wheel.
Caution
The wrong wheel can also
cause problems with bearing
life, brake cooling,
speedometer or odometer
calibration, headlamp aim,
bumper height, vehicle
ground clearance, and tire or
tire chain clearance to the
body and chassis.