2020 CADILLAC CT6 tire size

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
76 SEATS AND RESTRAINTS
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 071. If the vehicle has rollover roof-rail
airbags, see
Different Size Tires and
Wheels 0333 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 0378.
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 0121.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
172 DRIVING AND OPERATING
Fuel
Top Tier Fuel . . . . . . . . . . . . . . . . . . . . . 258
Recommended Fuel (3.6LV6 Engine) . . . . . . . . . . . . . . . . . . . . . . 258
Recommended Fuel (4.2L Twin Turbo V8 Engine) . . . . . . . . . . . . . . . 259
Prohibited Fuels . . . . . . . . . . . . . . . . . . 259
Fuels in Foreign Countries . . . . . . . 259
Fuel Additives . . . . . . . . . . . . . . . . . . . . 259
Filling the Tank . . . . . . . . . . . . . . . . . . 260
Filling a Portable Fuel Container . . . . . . . . . . . . . . . . . . . . . . . . 261
Trailer Towing
General Towing Information . . . . 262
Driving Characteristics andTowing Tips . . . . . . . . . . . . . . . . . . . . . 262
Trailer Towing . . . . . . . . . . . . . . . . . . . . 266
Towing Equipment . . . . . . . . . . . . . . . 267
Conversions and Add-Ons
Add-On Electrical Equipment . . . 269
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.
. 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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
180 DRIVING AND OPERATING
{Warning
Do not load the vehicle any
heavier than the Gross Vehicle
Weight Rating (GVWR),
or either the maximum front or
rear Gross Axle Weight Rating
(GAWR). This can cause
systems to break and change
the way the vehicle handles.
This could cause loss of control
and a crash. Overloading can
also reduce stopping distance,
damage the tires, and shorten
the life of the vehicle. Tire and Loading Information
Label
Label Example
A vehicle-specific Tire and
Loading Information label is
attached to the vehicle's center
pillar (B-pillar). The Tire and
Loading Information label shows
the number of occupant seating
positions (1), and the maximum
vehicle capacity weight (2) in
kilograms and pounds.
The Tire and Loading Information
label also shows the tire size of
the original equipment tires (3) and the recommended cold tire
inflation pressures (4). For more
information on tires and inflation
see
Tires 0315 and
Tire Pressure 0322.
There is also important loading
information on the Certification
label. It may show the Gross
Vehicle Weight Rating (GVWR)
and the Gross Axle Weight Rating
(GAWR) for the front and rear
axle. See “Certification Label” later
in this section.
“Steps for Determining Correct
Load Limit–
1.Locate the statement "The
combined weight of
occupants and cargo should
never exceed XXX kg or
XXX lbs." on your vehicle’s
placard.
2.Determine the combined
weight of the driver and
passengers that will be riding
in your vehicle.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
270 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 271
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 271
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 272
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 272
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 272
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 274
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 277
Engine Oil Life System . . . . . . . . . . . 280
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
Engine Air Filter Life System . . . . 281
Engine Air Cleaner/Filter . . . . . . . . . 282
Cooling System . . . . . . . . . . . . . . . . . . . 284
Engine Overheating . . . . . . . . . . . . . . 288
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 289
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Brake Pad Life System . . . . . . . . . . . 291
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 291 Battery - North America . . . . . . . . . 292
All-Wheel Drive . . . . . . . . . . . . . . . . . . 293
Starter Switch Check . . . . . . . . . . . . . 294
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 294
Wiper Blade Replacement . . . . . . . 295
Windshield Replacement . . . . . . . . 295
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 296
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 297
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 297
LED Lighting . . . . . . . . . . . . . . . . . . . . . 297
Electrical System
Electrical System Overload . . . . . . 298
Fuses and Circuit Breakers . . . . . . 298
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Instrument Panel Fuse Block . . . . 306
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
All-Season Tires . . . . . . . . . . . . . . . . . . 316
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 316
Low-Profile Tires . . . . . . . . . . . . . . . . . 317
Summer Tires . . . . . . . . . . . . . . . . . . . . 317
Tire Sidewall Labeling . . . . . . . . . . . 317 Tire Designations . . . . . . . . . . . . . . . . . 319
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 320
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 322
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 324
Tire Pressure Monitor System . . . 324
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 325
Tire Inspection . . . . . . . . . . . . . . . . . . . 329
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 329
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Buying New Tires . . . . . . . . . . . . . . . . 331
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Uniform Tire Quality Grading . . . 333
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 334
Wheel Replacement . . . . . . . . . . . . . . 335
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 335
If a Tire Goes Flat . . . . . . . . . . . . . . . . 336
Tire Changing . . . . . . . . . . . . . . . . . . . . . 337
Compact Spare Tire . . . . . . . . . . . . . . 342Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . . . 343

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
316 VEHICLE CARE
Warning (Continued)
.Replace any tires that have
been damaged by impacts
with potholes, curbs, etc.
.Improperly repaired tires
can cause a crash. Only
the dealer or an authorized
tire service center should
repair, replace, dismount,
and mount the tires.
.Do not spin the tires in
excess of 56 km/h
(35 mph) on slippery
surfaces such as snow,
mud, ice, etc. Excessive
spinning may cause the
tires to explode.
See Tire Pressure for High-Speed
Operation 0324 for inflation
pressure adjustment for
high-speed driving.
All-Season Tires
This vehicle may come with all-season
tires. These tires are designed to
provide good overall performance on
most road surfaces and weather
conditions. Original equipment tires
designed to GM's specific tire
performance criteria have a TPC
specification code molded onto the
sidewall. Original equipment
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 0316.
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
0 331.
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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
VEHICLE CARE 317
Low-Profile Tires
If the vehicle has 245/45R19,
245/40R20, or 245/40ZR20 size
tires, they are classified as
low-profile tires.Caution
Low-profile tires are more
susceptible to damage from road
hazards or curb impact than
standard profile tires. Tire and/or
wheel assembly damage can occur
when coming into contact with
road hazards like potholes, or sharp
edged objects, or when sliding into
a curb. The warranty does not cover
this type of damage. Keep tires set
to the correct inflation pressure and
when possible, avoid contact with
curbs, potholes, and other road
hazards.
Summer Tires
This vehicle may come with
245/40ZR20 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 0316.
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
(Continued)
Caution (Continued)
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
0 329.
Tire Sidewall Labeling
Useful information about a tire is
molded into its sidewall. The
examples show a typical passenger
vehicle tire and a compact spare
tire sidewall.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
318 VEHICLE CARE
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
see Uniform Tire Quality Grading
0 333.
(7) Maximum Cold Inf lation
Load Limit
:Maximum load that
can be carried and the maximum
pressure needed to support
that load.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
VEHICLE CARE 319
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, see Compact
Spare Tire 0342 and
If a Tire Goes Flat 0336. (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 Inf lation
Load Limit
:Maximum load that
can be carried and the maximum
pressure needed to support
that load.
(5) Tire Inf lation
: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 0322.
(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.