wheel size CADILLAC XT6 2021 Owner's Manual

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
SEATS AND RESTRAINTS 71
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet metal
may keep the airbag system from
working properly.
The operation of the airbag system
can also be affected by changing,
including improperly repairing or
replacing, any parts of the following:
.Airbag system, including airbag
modules, front or side impact
sensors, sensing and diagnostic
module, or airbag wiring
.Front seats, including stitching,
seams or zippers
.Seat belts
.Steering wheel, instrument panel,
overhead console, ceiling trim,
or pillar garnish trim
.Inner door seals, including speakers
Your dealer and the service manual
have information about the location of
the airbag modules and sensors, sensing and diagnostic module, and
airbag wiring along with the proper
replacement procedures.
In addition, the vehicle has a
passenger sensing system for the front
outboard passenger position, which
includes sensors that are part of the
passenger seat. The passenger sensing
system may not operate properly if
the original seat trim is replaced with
non-GM covers, upholstery, or trim; or
with GM covers, upholstery, or trim
designed for a different vehicle. Any
object, such as an aftermarket seat
heater or a comfort-enhancing pad or
device, installed under or on top of
the seat fabric, could also interfere
with the operation of the passenger
sensing system. This could either
prevent proper deployment of the
passenger airbag(s) or prevent the
passenger sensing system from
properly turning off the passenger
airbag(s). See
Passenger Sensing
System 066.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires and
Wheels 0354 for additional important
information. If the vehicle must be modified
because you have a disability and have
questions about whether the
modifications will affect the vehicle's
airbag system, or if you have
questions about whether the airbag
system will be affected if the vehicle is
modified for any other reason, call
Customer Assistance. See
Customer
Assistance Offices 0399.
Airbag System Check
The airbag system does not need
regularly scheduled maintenance or
replacement. Make sure the airbag
readiness light is working. See Airbag
Readiness Light 0114.
Caution
If an airbag covering is damaged,
opened, or broken, the airbag may
not work properly. Do not open or
break the airbag coverings. If there
are any opened or broken airbag
coverings, have the airbag covering
and/or airbag module replaced. For
the location of the airbags, see
Where Are the Airbags? 062. See
your dealer for service.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
218 DRIVING AND OPERATING
Fuels in Foreign Countries . . . . . . . 287
Fuel Additives . . . . . . . . . . . . . . . . . . . . 287
Filling the Tank . . . . . . . . . . . . . . . . . . 287
Filling a Portable FuelContainer . . . . . . . . . . . . . . . . . . . . . . . . 289
Trailer Towing
General Towing Information . . . . 289
Driving Characteristics and
Towing Tips . . . . . . . . . . . . . . . . . . . . . 290
Trailer Towing . . . . . . . . . . . . . . . . . . . . 293
Towing Equipment . . . . . . . . . . . . . . . 297
Trailer Sway Control (TSC) . . . . . . 300
Conversions and Add-Ons
Add-On Electrical Equipment . . . 301
Driving Information
Driving for Better Fuel
Economy
Driving habits can affect fuel mileage.
Here are some driving tips to get the
best fuel economy possible.
.Set the climate controls to the
desired temperature after the engine
is started, or turn them off when
not required.
.On AWD vehicles, use Tour Mode
when conditions permit.
.Avoid fast starts and accelerate
smoothly.
.Brake gradually and avoid abrupt
stops.
.Avoid idling the engine for long
periods of time.
.When road and weather conditions
are appropriate, use cruise control.
.Always follow posted speed limits or
drive more slowly when conditions
require.
.Keep vehicle tires properly inflated.
.Combine several trips into a
single trip.
.Replace the vehicle's tires with the
same TPC Spec number molded into
the tire's sidewall near the size.
.Follow recommended scheduled
maintenance.
Distracted Driving
Distraction comes in many forms and
can take your focus from the task of
driving. Exercise good judgment and
do not let other activities divert your
attention away from the road. Many
local governments have enacted laws
regarding driver distraction. Become
familiar with the local laws in
your area.
To avoid distracted driving, keep your
eyes on the road, keep your hands on
the steering wheel, and focus your
attention on driving.
.Do not use a phone in demanding
driving situations. Use a hands-free
method to place or receive
necessary phone calls.
.Watch the road. Do not read, take
notes, or look up information on
phones or other electronic devices.
.Designate a front seat passenger to
handle potential distractions.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
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DRIVING AND OPERATING 271
After completely passing a large
enough space, an audible beep occurs.
A red stop symbol and a shift to
reverse message are displayed.
If the vehicle is in R (Reverse), but
does not steer into the expected
space, this may be because the system
is maneuvering the vehicle into a
previously detected space. The APA
system does not need service.
APA will instruct the vehicle to stop
once a large enough space is found.
Follow the displayed instructions.
Shift to R (Reverse) to engage
automatic steering. The steering wheel
will vibrate briefly as a reminder to
remove hands from the steering
wheel. APA uses idle speed and
braking to park. If idle speed is not
sufficient, gently press the accelerator.Check surroundings and be prepared
to stop to avoid vehicles, pedestrians,
or objects not detected by the system.
In case the driver brakes, APA will not
disengage. Manual steering by the
driver automatically disengages APA.
Vehicle speed is limited to a
maximum of 5 km/h (3 mph) during
the parking maneuver.
A progress arrow displays the status
of the parking maneuver. Depending
on the space size, additional
maneuvers may be required, and there
will be additional instructions. When
changing gears, allow the automatic
steering to complete before continuing
the parking maneuver. APA will beep
and display a PARKING COMPLETE
message. Apply the brakes and place
the vehicle in P (Park).
APA may automatically disengage if:
.The steering wheel is used by the
driver.
.The maximum allowed speed is
exceeded.
.The parking brake is applied or the
vehicle is shifted into P (Park).
.There is a failure with the APA
system.
.Electronic stability control or
antilock brakes are activated.
.A high priority vehicle message is
displayed in the DIC.
.The driver opens the door with an
unbuckled seat belt.
The brake holds the vehicle until the
parking brake or brake is applied,
or the vehicle is shifted into P (Park).
To cancel APA, press
Oagain.
When the System Does Not Seem to
Work Properly
The APA system may require a short
period of driving along curves to
calibrate.
Rear Pedestrian Alert
Under certain conditions, this feature
can provide alerts for a pedestrian
within the system’s range directly
behind the vehicle. This feature only
works in R (Reverse) below 12 km/h
(8 mph), and detects pedestrians up to
8 m (26 ft) away during daytime
driving. During nighttime driving,
feature performance is very limited.

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VEHICLE CARE 303
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 304
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 304
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 305
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 305
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 305
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 308
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 311
Engine Oil Life System . . . . . . . . . . . 313
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Engine Air Filter Life System . . . . 314
Engine Air Cleaner/Filter . . . . . . . . . 315
Cooling System . . . . . . . . . . . . . . . . . . . 316
Engine Overheating . . . . . . . . . . . . . . 320
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 321
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 322 Battery - North America . . . . . . . . . 323
All-Wheel Drive . . . . . . . . . . . . . . . . . . 324
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 324
Wiper Blade Replacement . . . . . . . 325
Windshield Replacement . . . . . . . . 326
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 326
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 327
Bulb Replacement
LED Lighting . . . . . . . . . . . . . . . . . . . . . 327
Electrical System
Electrical System Overload . . . . . . 327
Fuses and Circuit Breakers . . . . . . 328
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Instrument Panel Fuse Block . . . . 332
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
All-Season Tires . . . . . . . . . . . . . . . . . . 337
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 338
Summer Tires . . . . . . . . . . . . . . . . . . . . 338
Tire Sidewall Labeling . . . . . . . . . . . 339 Tire Designations . . . . . . . . . . . . . . . . . 340
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 341
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 343
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 345
Tire Pressure Monitor System . . . 346
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 347
Tire Inspection . . . . . . . . . . . . . . . . . . . 350
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 351
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
Buying New Tires . . . . . . . . . . . . . . . . 353
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 354
Uniform Tire Quality Grading . . . 354
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Wheel Replacement . . . . . . . . . . . . . . 356
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 356
If a Tire Goes Flat . . . . . . . . . . . . . . . . 357
Tire Changing . . . . . . . . . . . . . . . . . . . . . 358
Compact Spare Tire . . . . . . . . . . . . . . 364
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . . . 364

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
338 VEHICLE CARE
all-season tires can be identified by
the last two characters of this TPC
code, which will be“MS.”
Consider installing winter tires on the
vehicle if frequent driving on snow or
ice-covered roads is expected.
All-season tires provide adequate
performance for most winter driving
conditions, but they may not offer the
same level of traction or performance
as winter tires on snow or ice-covered
roads. See Winter Tires 0338.
Winter Tires
This vehicle was not originally
equipped with winter tires. Winter
tires are designed for increased
traction on snow and ice-covered
roads. Consider installing winter tires
on the vehicle if frequent driving on
ice or snow covered roads is expected.
See your dealer for details regarding
winter tire availability and proper tire
selection. Also, see Buying New Tires
0 353.
With winter tires, there may be
decreased dry road traction, increased
road noise, and shorter tread life. After changing to winter tires, be alert
for changes in vehicle handling and
braking.
If using winter tires:
.Use tires of the same brand and
tread type on all four wheel
positions.
.Use only radial ply tires of the same
size, load range, and speed rating as
the original equipment tires.
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. If winter
tires with a lower speed rating are
chosen, never exceed the tire's
maximum speed capability.
Summer Tires
This vehicle may come with 235/
65R18 or 235/55R20 high performance
summer tires. These tires have a
special tread and compound that are
optimized for maximum dry and wet
road performance. This special tread
and compound will have decreased
performance in cold climates, and on
ice and snow. It is recommended that
winter 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 0338.
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 or blow heated air
directly on the tires. Always inspect
tires before use. See Tire Inspection
0 350.

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VEHICLE CARE 341
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).
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
:A rubber coated layer of
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
:A pneumatic tire in
which the plies are laid at
alternate angles less than
90 degrees to the centerline of the
tread.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
VEHICLE CARE 347
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
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
0 347.
See Radio Frequency Statement 0406.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 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 0228. 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 at each
ignition cycle until the tires are
inflated to the correct inflation
pressure. 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) 0124.
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 0228, for an
example of the Tire and Loading
Information label and its location.
Also see Tire Pressure 0343.

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VEHICLE CARE 351
.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 every
12 000 km (7,500 mi). See
Maintenance Schedule0380.
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 0352 and
Wheel Replacement 0356.
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 0343 and
Vehicle Load Limits 0228. Reset the Tire Pressure Monitor
System. See
Tire Pressure Monitor
Operation 0347.
Check that all wheel nuts are
properly tightened. See “Wheel
Nut Torque ”under Capacities and
Specifications 0394, and
“Removing the Flat Tire and
Installing the Spare Tire ”under
Tire Changing 0358.
{Warning
Rust or dirt on a wheel, or on
the parts to which it is fastened,
can cause wheel nuts to become
loose over time. The wheel
could come off and cause a
crash. When changing a wheel,
remove any rust or dirt from
places where the wheel attaches
to the vehicle. In an emergency,
a cloth or paper towel can be
used; however, use a scraper or
wire brush later to remove all
rust or dirt.

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VEHICLE CARE 353
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 Specnumber will be followed by MS for
mud and snow. See
Tire Sidewall
Labeling 0339 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 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 Rotation 0351.
{Warning
Tires could explode during
improper service. Attempting to
mount or dismount a tire could
cause injury or death. Only your
(Continued)
Warning (Continued)
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
(Continued)

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354 VEHICLE CARE
Warning (Continued)
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 0228.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 0353 and
Accessories and Modifications 0305.
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