tire size CADILLAC CT6 2018 1.G Owners Manual

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
32 IN BRIEF
If the CHANGE ENGINE OIL
SOON message is not on, the
system is reset.
See Engine Oil Life System 0309.
Driving for Better Fuel
Economy (Gasoline Only)
Driving habits can affect fuel mileage.
Here are some driving tips to get the
best fuel economy possible.
.
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.Driving for Better Energy
Efficiency (PLUG-IN Only)
Use the following tips to help
maximize energy efficiency and range.
In colder temperatures, while these
efficiency tips will help, the electric
vehicle driving range may be lower
due to higher energy usage.
Driving Style
Acceleration/Braking/Coasting
Avoid unnecessary rapid accelerations
and decelerations.
Electric range is maximized at
80 km/h (50 mph) and below. Higher
speeds use more energy and can
significantly reduce electric range.
Use cruise control when appropriate. Plan ahead for decelerations and coast
whenever possible. For example, do
not rush to traffic signals.
Do not shift to N (Neutral) to coast.
The vehicle recovers energy while
coasting and braking in D (Drive) or M
(Manual Mode).
Drive Mode and PRNDM Selection
Use Tour Mode when possible.
Sport Mode provides more responsive
acceleration than Tour Mode but can
reduce efficiency.
Use Hold Mode on a trip where it is
expected that all of the electric charge
will be depleted. Use Hold Mode
mainly during highway or high speed
driving to maximize both EV miles
and fuel efficiency.
Use M (Manual Model) in heavy
stop-and-go traffic or when traveling
downhill. M (Manual Mode) requires
less brake pedal application and
provides a controlled, efficient way to
slow the vehicle down.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
SEATS AND RESTRAINTS 95
Servicing the
Airbag-Equipped Vehicle
Airbags affect how the vehicle should
be serviced. There are parts of the
airbag system in several places around
the vehicle. Your dealer and the
service manual have information
about servicing the vehicle and the
airbag system. To purchase a service
manual, seeService Publications
Ordering Information 0416.
{Warning
For up to 10 seconds after the
vehicle is turned off and the 12‐volt
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
are close to an airbag when it
inflates. Avoid yellow connectors.
They are probably part of the airbag
system. Be sure to follow proper
service procedures, and make sure
the person performing work for you
is qualified to do so.
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 any parts of the front seats,
seat belts, airbag sensing and
diagnostic module, steering wheel,
instrument panel, any of the airbag
modules, ceiling or pillar garnish trim,
overhead console, front sensors, side
impact sensors, or airbag wiring.
Your dealer and the service manual
have information about the location of
the airbag sensors, sensing and
diagnostic module, and airbag wiring.
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 091.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires and
Wheels 0357 for additional important
information.
If you have to modify your vehicle
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 0410.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
214 DRIVING AND OPERATING
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
seeTires 0340 and Tire Pressure
0 347.
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.
3.Subtract the combined weight
of the driver and passengers
from XXX kg or XXX lbs.
4.The resulting figure equals
the available amount of cargo
and luggage load capacity. For
example, if the "XXX" amount
equals 1400 lbs. and there
will be five 150 lb passengers
in your vehicle, the amount
of available cargo and luggage
load capacity is 650 lbs.
(1400-750 (5 x 150) =
650 lbs.)
5.Determine the combined
weight of luggage and cargo
being loaded on the vehicle.
That weight may not safely
exceed the available cargo
and luggage load capacity
calculated in Step 4.
6.If your vehicle will be towing
a trailer, load from your
trailer will be transferred to
your vehicle. Consult this
manual to determine how
this reduces the available
cargo and luggage load
capacity of your vehicle.”
See Trailer Towing (PLUG-IN Only)
0 293 orTrailer Towing (Gasoline
Only) 0293 for important
information on towing a trailer,
towing safety rules, and
trailering tips.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
296 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 297
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 297
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 297
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 298
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 298
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 300
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 307
Engine Oil Life System . . . . . . . . . . . 309
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Engine Air Cleaner/Filter . . . . . . . . . 311
Cooling System (Gasoline Only) . . . . . . . . . . . . . . . . . 312
Cooling System (PLUG-IN Only) . . . . . . . . . . . . . . . . . 316
Engine Overheating . . . . . . . . . . . . . . 321
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 322
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 323 Battery - North America . . . . . . . . . 324
All-Wheel Drive . . . . . . . . . . . . . . . . . . 326
Starter Switch Check . . . . . . . . . . . . . 326
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . 327
Wiper Blade Replacement . . . . . . . 327
Windshield Replacement . . . . . . . . 328
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 328
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . . . . . 329
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 330
LED Lighting . . . . . . . . . . . . . . . . . . . . . 330
License Plate Lamp . . . . . . . . . . . . . . 330
Replacement Bulbs . . . . . . . . . . . . . . . 330
Electrical System
Electrical System Overload . . . . . . 331
Fuses and Circuit Breakers . . . . . . 331
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Instrument Panel Fuse Block . . . . 335
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 All-Season Tires . . . . . . . . . . . . . . . . . . 341
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 341
Low-Profile Tires . . . . . . . . . . . . . . . . . 342
Summer Tires . . . . . . . . . . . . . . . . . . . . 342
Tire Sidewall Labeling . . . . . . . . . . . 342
Tire Designations . . . . . . . . . . . . . . . . . 344
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 345
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 347
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 349
Tire Pressure Monitor System . . . 349
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 350
Tire Inspection . . . . . . . . . . . . . . . . . . . 353
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 353
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Buying New Tires . . . . . . . . . . . . . . . . 355
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 357
Uniform Tire Quality Grading . . . 357
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 359
Wheel Replacement . . . . . . . . . . . . . . 359
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 360
If a Tire Goes Flat . . . . . . . . . . . . . . . . 360
Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 362
Storing the Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 368

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
VEHICLE CARE 341
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 0349 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 0341.
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
0 355.
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-11292458) -
2018 - crc - 2/15/17
342 VEHICLE CARE
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 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
0341.
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
(Continued)
Caution (Continued)
which they are installed. Do not
apply heat or blow heated air
directly on the tires. Always inspect
tires before use. SeeTire Inspection
0 353.
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-11292458) -
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VEHICLE CARE 343
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
0 357.
(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-11292458) -
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344 VEHICLE CARE
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 0373
and If a Tire Goes Flat 0360. (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 0347.
(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 following is an example of a
typical passenger vehicle tire size.
(1) Passenger (P-Metric) Tire:
The United States version of a
metric tire sizing system. The
letter P as the first character in

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
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VEHICLE CARE 345
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire and
Rim Association.
(2) Tire Width
:The three-digit
number indicates the tire section
width in millimeters from sidewall
to sidewall.
(3) Aspect Ratio
:A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size aspect
ratio is 60, as shown in item 3 of
the illustration, it would mean
that the tire's sidewall is
60 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;
and the letter B means belted-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.
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 0347.
Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including the
maximum capacity of fuel, oil, and
coolant, but without passengers
and cargo.

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VEHICLE CARE 347
placard.
SeeTire Pressure 0347 and Vehicle
Load Limits 0213.
Radial Ply Tire
:A pneumatic tire
in which the ply cords that extend
to the beads are laid at 90 degrees
to the centerline of the tread.
Rim
:A metal support for a tire
and upon which the tire beads are
seated.
Sidewall
:The portion of a tire
between the tread and the bead.
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 0355.
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 0357.
Vehicle Capacity Weight
:The
number of designated seating
positions multiplied by
68 kg (150 lb) plus the rated cargo
load. See Vehicle Load Limits 0213.
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 capacity
weight and the original equipment
tire size and recommended
inflation pressure. See “Tire and
Loading Information Label” under
Vehicle Load Limits 0213.
Tire Pressure
Tires need the correct amount of
air pressure to operate effectively.
Caution
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.
(Continued)