tire size CADILLAC XT4 2023 User Guide

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
16412876) - 2023 - CRC - 3/25/22
Vehicle Care 369
(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 see
Tire Pressure 0372.
(6) Tire Size
:A
combination of 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 example shows a
typical passenger vehicle
tire size.
Passenger (P-Metric) Tire
(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 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.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
16412876) - 2023 - CRC - 3/25/22
372 Vehicle Care
Speed Rating:An
alphanumeric code
assigned to a tire indicating
the maximum speed at
which a tire can operate.
Traction
:The friction
between the tire and the
road surface. The amount
of grip provided.
Tread
:The portion of a
tire that comes into
contact with the road.
Treadwear Indicators
:
Narrow bands, sometimes
called wear bars, that show
across the tread of a tire
when only 1.6 mm (1/16 in)
of tread remains. See
When It Is Time for New
Tires 0382.
UTQGS (Uniform Tire
Quality Grading
Standards)
:A tire
information system that
provides consumers with
ratings for a tire's traction, temperature, and
treadwear. Ratings are
determined by tire
manufacturers using
government testing
procedures. The ratings
are molded into the
sidewall of the tire. See
Uniform Tire Quality
Grading
0385.
Vehicle Capacity Weight
:
The number of designated
seating positions multiplied
by 68 kg (150 lbs) plus the
rated cargo load. See
Vehicle Load Limits 0242.
Vehicle Maximum Load on
the Tire
:Load on an
individual tire due to curb
weight, accessory weight,
occupant weight, and cargo
weight.
Vehicle Placard
:A label
permanently attached to a
vehicle showing the
vehicle's capacity weight and the original equipment
tire size and recommended
inflation pressure. See
“Tire
and Loading Information
Label” under Vehicle Load
Limits 0242.
Tire Pressure
Tires need the correct
amount of air pressure to
operate effectively.
{Warning
Neither tire underinflation
nor overinflation is good.
Underinflated tires,
or tires that do not have
enough air, can result in:
.Tire overloading and
overheating, which
could lead to a blowout
.Premature or
irregular wear
.Poor handling
(Continued)

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
16412876) - 2023 - CRC - 3/25/22
374 Vehicle Care
pressure is low, add air
until the recommended
pressure is reached. If the
inflation pressure is high,
press on the metal stem in
the center of the tire valve
to release air.
Recheck the tire pressure
with the tire gauge.
Put the valve caps back on
the valve stems to keep out
dirt and moisture. Use only
valve caps designed for the
vehicle by GM. TPMS
sensors could be damaged
and would not be covered
by the vehicle warranty.
Tire Pressure for
High-Speed Operation
{Warning
Driving at high speeds,
160 km/h (100 mph) or
higher, puts additional strain(Continued)
Warning (Continued)
on tires. Sustained
high-speed driving causes
excessive heat buildup and
can cause sudden tire
failure. This could cause a
crash, and you or others
could be killed. Some
high-speed rated tires
require inflation pressure
adjustment for high-speed
operation. When speed
limits and road conditions
allow the vehicle to be
driven at high speeds, make
sure the tires are rated for
high-speed operation, are in
excellent condition, and are
set to the correct cold tire
inflation pressure for the
vehicle load. Vehicles with tire sizes listed
in the High Speed Operation
Inflation Pressures table
require inflation pressure
adjustment when driving the
vehicle at speeds of 160 km/h
(100 mph) or higher. Set the
cold tire inflation pressure to
the corresponding value in the
table for the tire size on the
vehicle.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
16412876) - 2023 - CRC - 3/25/22
Vehicle Care 375
High Speed Operation Inflation Pressures
Tire Size Cold Inflation Pressure kPa (psi)
235/55R18 260 kPa (38 psi)
245/45R20 260 kPa (38 psi)
Return the tires to the
recommended cold tire
inflation pressure when
high-speed driving has ended.
See Vehicle Load Limits 0242
and Tire Pressure 0372.
Tire Pressure Monitor
System
The Tire Pressure Monitor
System (TPMS) uses radio and
sensor technology to check
tire pressure levels. The TPMS
sensors monitor the air
pressure in your tires and
transmit tire pressure
readings to a receiver located
in the vehicle.
Each tire, including the spare
(if provided), should be
checked monthly when cold and inflated to the inflation
pressure recommended by the
vehicle manufacturer on the
vehicle placard or tire inflation
pressure label. (If your vehicle
has tires of a different size
than the size indicated on the
vehicle placard or tire inflation
pressure label, you should
determine the proper tire
inflation pressure for those
tires.)
As an added safety feature,
your vehicle has been
equipped with a tire pressure
monitoring system (TPMS)
that illuminates a low tire
pressure telltale when one or
more of your tires is
significantly under-inflated.
Accordingly, when the low tire
pressure telltale illuminates,
you should stop and check
your tires as soon as possible,
and inflate them to the proper
pressure. Driving on a
significantly under-inflated tire
causes the tire to overheat
and can lead to tire failure.
Under-inflation also reduces
energy efficiency and tire
tread life, and may affect the
vehicle's handling and
stopping ability.
Please note that the TPMS is
not a substitute for proper tire
maintenance, and it is the
driver's responsibility to
maintain correct tire pressure,
even if under-inflation has not

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 377
Using the DIC, tire pressure
levels can be viewed. For
additional information and
details about the DIC
operation and displays see
Driver Information Center
(DIC)0136.
The low tire pressure warning
light may come on in cool
weather when the vehicle is
first started, and then turn off
as the vehicle is driven. This
could be an early indicator
that the air pressure is getting
low and needs to be inflated to
the proper pressure.
A Tire and Loading
Information label, attached to
your vehicle, shows the size of
the original equipment tires
and the correct inflation
pressure for the tires when
they are cold. See Vehicle
Load Limits 0242, for an
example of the Tire and
Loading Information label and
its location. Also see Tire
Pressure 0372. The TPMS can warn about a
low tire pressure condition but
it does not replace normal tire
maintenance. See Tire
Inspection
0380, Tire
Rotation 0381, and Tires
0 364.
Caution
Tire sealant materials are
not all the same.
A non-approved tire sealant
could damage the TPMS
sensors. TPMS sensor
damage caused by using an
incorrect tire sealant is not
covered by the vehicle
warranty. Always use only
the GM approved tire
sealant available through
your dealer or included in
the vehicle.
Factory-installed Tire Inflator
Kits use a GM approved liquid
tire sealant. Using
non-approved tire sealants
could damage the TPMS sensors. See Tire Sealant and
Compressor Kit
0390 for
information regarding the
inflator kit materials and
instructions.
TPMS Malfunction Light
and Message
The TPMS will not function
properly if one or more of the
TPMS sensors are missing or
inoperable. When the system
detects a malfunction, the low
tire pressure warning light
flashes for about one minute
and then stays on for the
remainder of the ignition cycle.
A DIC warning message also
displays. The malfunction light
and DIC warning message
come on at each ignition cycle
until the problem is corrected.
Some of the conditions that
can cause these to come
on are:
.One of the road tires has
been replaced with the
spare tire. The spare tire
does not have a TPMS
sensor. The malfunction light

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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Vehicle Care 381
.There is cord or fabric
showing through the
tire's rubber.
.The tread or sidewall is
cracked, cut, or snagged
deep enough to show
cord or fabric.
.The tire has a bump,
bulge, or split.
.The tire has a puncture,
cut, or other damage that
cannot be repaired well
because of the size or
location of the damage.
Tire Rotation
Tires should be rotated
according to the interval
specified in the
Maintenance Schedule. See
Maintenance Schedule
0425. Tires are rotated to
achieve a more uniform
wear for all tires. The first
rotation is the most
important.
Anytime unusual wear is
noticed, rotate the tires as
soon as possible, check for
proper tire inflation
pressure, and check for
damaged tires or wheels.
If the unusual wear
continues after the
rotation, check the wheel
alignment. See When It Is
Time for New Tires
0382
and Wheel Replacement
0 387.
Use this rotation pattern
when rotating the tires.
Do not include the compact
spare tire in the tire
rotation.
Adjust the front and rear
tires to the recommended
inflation pressure on the
Tire and Loading
Information label after the
tires have been rotated.
See Tire Pressure 0372
and Vehicle Load Limits
0 242.

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Vehicle Care 383
The rubber in tires ages over
time. This also applies to the
spare tire, if the vehicle has
one, even if it is never used.
Multiple factors including
temperatures, loading
conditions, and inflation
pressure maintenance affect
how fast aging takes place.
GM recommends that tires,
including the spare if
equipped, be replaced after six
years, regardless of tread
wear. To identify the age of a
tire, use the tire manufacture
date, which is the last four
digits of the DOT Tire
Identification Number (TIN)
molded into one side of the
tire sidewall. The last four
digits of the TIN indicate the
tire manufactured date. The
first two digits represent the
week and the last two digits,
the year. For example, the
third week of the year 2020
would have a 4-digit DOT date
of 0320. Week 01 is the first
full week (Sunday through
Saturday) of each year.Vehicle Storage
Tires age when stored
normally mounted on a parked
vehicle. Park a vehicle that will
be stored for at least a month
in a cool, dry, clean area away
from direct sunlight to slow
aging. This area should be free
of grease, gasoline, or other
substances that can
deteriorate rubber.
Parking for an extended
period can cause flat spots on
the tires that may result in
vibrations while driving. When
storing a vehicle for at least a
month, remove the tires or
raise the vehicle to reduce the
weight from the tires.
Buying New Tires
GM has developed and
matched specific tires for
the vehicle. The original
equipment tires installed
were designed to meet
General Motors Tire
Performance CriteriaSpecification (TPC Spec)
system rating. When
replacement tires are
needed, GM strongly
recommends buying tires
with the same TPC Spec
rating.
GM's exclusive TPC Spec
system considers over a
dozen critical specifications
that impact the overall
performance of the vehicle,
including brake system
performance, ride and
handling, traction control,
and tire pressure
monitoring performance.
GM's TPC Spec number is
molded onto the tire's
sidewall near the tire size.
If the tires have an
all-season tread design, the
TPC Spec number will be
followed by MS for mud
and snow. See Tire
Sidewall Labeling
0367 for
additional information.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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384 Vehicle Care
GM recommends replacing
worn tires in complete sets
of four. Uniform tread
depth on all tires will help
to maintain the
performance of the vehicle.
Braking and handling
performance may be
adversely affected if all the
tires are not replaced at
the same time. If proper
rotation and maintenance
have been done, all four
tires should wear out at
about the same time.
However, if it is necessary
to replace only one axle set
of worn tires, place the
new tires on the rear axle.
See Tire Rotation0381.
{Warning
Tires could explode
during improper service.
Attempting to mount or
dismount a tire could
(Continued)
Warning (Continued)
cause injury or death.
Only your dealer or
authorized tire service
center should mount or
dismount the tires.
{Warning
Mixing tires of different
sizes (other than those
originally installed on the
vehicle), brands, tread
patterns, or types may
cause loss of vehicle
control, resulting in a
crash or other vehicle
damage. Use the correct
size, brand, and type of
tire on all wheels.
{Warning
Using bias-ply tires on
the vehicle may cause the
wheel rim flanges to
develop cracks after
many miles of driving.
A tire and/or wheel could
fail suddenly and cause a
crash. Use only radial-ply
tires with the wheels on
the vehicle.
Winter tires with the same
speed rating as the original
equipment tires may not be
available for H, V, W, Y and
ZR speed rated tires. Never
exceed the winter tires’
maximum speed capability
when using winter tires
with a lower speed rating.
If the vehicle tires must be
replaced with a tire that
does not have a TPC Spec
number, make sure they
are the same size, load

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Vehicle Care 385
range, speed rating, and
construction (radial) as the
original tires.
The Tire and Loading
Information label indicates
the original equipment tires
on the vehicle. See Vehicle
Load Limits0242.
Different Size Tires
and Wheels
If wheels or tires are installed
that are a different size than
the original equipment wheels
and tires, vehicle performance,
including its braking, ride and
handling characteristics,
stability, and resistance to
rollover may be affected. If the
vehicle has electronic systems
such as antilock brakes,
rollover airbags, traction
control, electronic stability
control, or All-Wheel Drive, the
performance of these systems
can also be affected.
{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 0383
and Accessories and
Modifications 0327.
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.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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388 Vehicle Care
Warning (Continued)
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.
Tire Chains
{Warning
If the vehicle has 235/60R18
or 245/45R20 size tires, do
not use tire chains. There is(Continued)
Warning (Continued)
not enough clearance. Tire
chains used on a vehicle
without the proper amount
of clearance can cause
damage to the brakes,
suspension, or other vehicle
parts. The area damaged by
the tire chains could cause
loss of control and a crash.
Use another type of traction
device only if its
manufacturer recommends
it for the vehicle's tire size
combination and road
conditions. Follow that
manufacturer's instructions.
To avoid vehicle damage,
drive slow and readjust or
remove the traction device if
it contacts the vehicle. Do
not spin the wheels. If
traction devices are used,
install them on the front
tires.
Caution
If the vehicle is equipped
with a tire size other than
235/60R18 or 245/45R20,
use tire chains only where
legal and only when
necessary. Use low profile
chains that add no more
than 12 mm thickness to the
tire tread and inner sidewall.
Use chains that are the
proper size for the tires.
Install them on the tires of
the front axle. Do not use
chains on the tires of the
rear axle. Tighten them as
tightly as possible with the
ends securely fastened.
Drive slowly and follow the
chain manufacturer's
instructions. If the chains
contact the vehicle, stop and
retighten them. If the
contact continues, slow
down until it stops. Driving(Continued)