tire size CADILLAC XT4 2024 User Guide

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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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.
(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.

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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 0298.
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 0301. Vehicle Capacity Weight
:The number
of designated seating positions
multiplied by 68 kg (150 lbs) plus the
rated cargo load. See Vehicle Load
Limits 0170.
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 0170.
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
.Reduced fuel economy for
internal combustion engine
vehicles
.Reduced range for electric vehicles
Overinflated tires, or tires that have
too much air, can result in:
.Unusual wear
.Poor handling
.Rough ride
.Needless damage from road
hazards

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The Tire and Loading Information label
on the vehicle indicates the original
equipment tires and the correct cold
tire inflation pressures. The
recommended pressure is the minimum
air pressure needed to support the
vehicle's maximum load carrying
capacity. SeeVehicle Load Limits 0170.
How the vehicle is loaded affects
vehicle handling and ride comfort.
Never load the vehicle with more
weight than it was designed to carry.
When to Check
Check the pressure of the tires once a
month or more. Do not forget the
spare, if the vehicle has one. The
compact spare cold tire pressure should
be at 420 kPa (60 psi). See Compact
Spare Tire 0315.
How to Check
Use a good quality pocket-type gauge
to check tire pressure. Proper tire
inflation cannot be determined by
looking at the tire. Check the tire
inflation pressure when the tires are cold, meaning the vehicle has not been
driven for at least three hours or no
more than 1.6 km (1 mi).
Remove the valve cap from the tire
valve stem. Press the tire gauge firmly
onto the valve to get a pressure
measurement. If the cold tire inflation
pressure matches the recommended
pressure on the Tire and Loading
Information label, no further adjustment
is necessary. If the inflation 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 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.

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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
0 170 and
Tire Pressure 0292.
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-inflationhas not reached the level to trigger
illumination of the TPMS low tire pressure
telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined
with the low tire pressure telltale. When the
system detects a malfunction, the telltale
will flash for approximately one minute and
then remain continuously illuminated. This
sequence will continue upon subsequent
vehicle start-ups as long as the malfunction
exists.
When the malfunction indicator is
illuminated, the system may not be able to
detect or signal low tire pressure as
intended. TPMS malfunctions may occur for
a variety of reasons, including the
installation of replacement or alternate tires
or wheels on the vehicle that prevent the

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TPMS from functioning properly. Always
check the TPMS malfunction telltale after
replacing one or more tires or wheels on
your vehicle to ensure that the replacement
or alternate tires and wheels allow the
TPMS to continue to function properly.
SeeTire Pressure Monitor Operation 0295.
See Radio Frequency Statement 0348.
Tire Pressure Monitor Operation
This vehicle may have a Tire Pressure
Monitor System (TPMS). The TPMS is
designed to warn the driver when a low tire
pressure condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire and
wheel assembly. The TPMS sensors monitor
the air pressure in the tires and transmit the
tire pressure readings to a receiver located
in the vehicle.
When a low tire pressure condition is
detected, the TPMS illuminates the low tire
pressure warning light located on the
instrument cluster. If the warning light
comes on, stop as soon as possible and
inflate the tires to the recommended
pressure shown on the Tire and Loading
Information label. See Vehicle Load Limits
0 170.
A message to check the pressure in a
specific tire displays in the Driver
Information Center (DIC). The low tire
pressure warning light and the DIC warning
message come on each time the vehicle is
started until the tires are inflated to the
correct inflation pressure. If the vehicle has
DIC buttons, tire pressure levels can be
viewed. For additional information and
details about the DIC operation and displays,
see Driver Information Center (DIC) 0111.
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 shows
the size of the original equipment tires and
the correct inflation pressure for the tires when they are cold. See
Vehicle Load Limits
0 170, for an example of the Tire and
Loading Information label and its location.
Also see Tire Pressure 0292.
The TPMS can warn about a low tire
pressure condition but it does not replace
normal tire maintenance. See Tire Inspection
0 297, Tire Rotation 0297, and Tires0286.
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 0304 for information
regarding the inflator kit materials and
instructions.

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while the turn signal lamp is still flashing,
briefly press the center of the valve stem.
When the recommended pressure is reached,
the horn sounds once.
If the turn signal lamp does not flash within
15 seconds after starting to inflate the tire,
the tire fill alert has not been activated or is
not working.
If the hazard warning flashers are on, the
tire fill alert visual feedback will not work
properly.
The TPMS will not activate the tire fill alert
properly under the following conditions:
.There is interference from an external
device or transmitter.
.The air pressure from the inflation device
is not sufficient to inflate the tire.
.There is a malfunction in the TPMS.
.There is a malfunction in the horn or turn
signal lamps.
.The TPMS sensor identification code is not
registered to the system.
.The TPMS sensor battery is low.If the tire fill alert does not operate due to
TPMS interference, move the vehicle about
1 m (3 ft) back or forward and try again.
If the tire fill alert feature is not working,
use a tire pressure gauge.
TPMS Sensor Matching Process
—Auto
Learn Function
Each TPMS sensor has a unique
identification code. The identification code
needs to be matched to a new tire/wheel
position after rotating the tires or replacing
one or more of the TPMS sensors. When a
tire is installed, the vehicle must be
stationary for about 20 minutes before the
system recalculates. The following relearn
process takes up to 10 minutes, driving at a
minimum speed of 20 km/h (12 mph).
A dash (-) or pressure value will display in
the DIC. See Driver Information Center (DIC)
0 111. A warning message displays in the DIC
if a problem occurs during the relearn
process.
Tire Inspection
We recommend that the tires, including
the spare tire, if the vehicle has one, be
inspected for signs of wear or damage
at least once a month. Replace the tire if:
.The indicators at three or more
places around the tire can be seen.
.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
0 330.
Tires are rotated to achieve a more
uniform wear for all tires. The first
rotation is the most important.

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Treadwear indicators are one way to tell
when it is time for new tires. Treadwear
indicators appear when the tires have only
1.6 mm (1/16 in) or less of tread remaining.
SeeTire Inspection 0297 and
Tire Rotation 0297.
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 Criteria Specification (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 0288 for additional
information.
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

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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. SeeTire Rotation0297.
{Warning
Tires could explode during improper
service. Attempting to mount or
dismount a tire could 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 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 Limits
0 170.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 0299 and
Accessories and Modifications 0261.

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Tire Chains
{Warning
If the vehicle has 235/60R18 or 245/45R20
size tires, do not use tire chains. There is
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
(Continued)
Caution (Continued)
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 too fast
or spinning the wheels with chains on
will damage the vehicle.
If a Tire Goes Flat
It is unusual for a tire to blow out while
driving, especially if the tires are maintained
properly. SeeTires0286. If air goes out of
a tire, it is much more likely to leak out
slowly. But if there is ever a blowout, here
are a few tips about what to expect and
what to do: If a front tire fails, the flat tire creates a
drag that pulls the vehicle toward that side.
Take your foot off the accelerator pedal and
grip the steering wheel firmly. Steer to
maintain lane position, and then gently
brake to a stop, well off the road,
if possible.
A rear blowout, particularly on a curve, acts
much like a skid and may require the same
correction as used in a skid. Stop pressing
the accelerator pedal and steer to straighten
the vehicle. It may be very bumpy and
noisy. Gently brake to a stop, well off the
road, if possible.
{Warning
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has been driven
on while severely underinflated or flat
may cause a blowout and a serious crash.
Never attempt to re-inflate a tire that has
been driven on while severely
underinflated or flat. Have your dealer or
an authorized tire service center repair or
replace the flat tire as soon as possible.

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Caution
Improperly tightened wheel nuts can lead
to brake pulsation and rotor damage. To
avoid expensive brake repairs, evenly
tighten the wheel nuts in the proper
sequence and to the proper torque
specification. SeeCapacities and
Specifications 0338 for the wheel nut
torque specification.
14. Tighten the wheel nuts firmly in a crisscross sequence, as shown.
15. Lower the jack all the way and remove the jack from under the vehicle.
16. Tighten the wheel nuts firmly with the wheel wrench. When reinstalling the wheel cover or center
cap on the full-size tire, tighten all five
plastic caps hand snug with the aid of the
wheel wrench and tighten them with the
wheel wrench an additional one-quarter of
a turn.
Caution
Wheel covers will not fit on the vehicle's
compact spare. If you try to put a wheel
cover on the compact spare, the cover or
the spare could be damaged.
Storing a Flat or Spare Tire and Tools
{Warning
Storing a jack, a tire, or other equipment
in the passenger compartment of the
vehicle could cause injury. In a sudden
stop or collision, loose equipment could
strike someone. Store all these in the
proper place.
To store the flat or spare tire and tools: 1. Open the liftgate. See Liftgate019.
2. Replace the jack and tools in their original storage location.
3. Lower the load floor. 4. Place the tire, lying flat, in the rear
storage compartment.
5. Place the loop end of the strap through the liftgate striker.6. Route the strap through the wheel asshown.
7. Attach the hook to the loop end of the strap.
8. Tighten the strap.
9. Replace the cargo cover, if equipped.
10. Close the liftgate and make sure it is fully latched.
The compact spare is for temporary use
only. Replace the compact spare tire with a
full-size tire as soon as you can.