2018 CADILLAC CT6 oil additives

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 287
by the vehicle warranty. If heavy
knocking is heard when using gasoline
rated at 93 octane, the engine needs
service.
Prohibited Fuels
Caution
Do not use fuels with any of the
following conditions; doing so may
damage the vehicle and void its
warranty:. For vehicles which are not
FlexFuel, fuel labeled greater
than 15% ethanol by volume,
such as mid-level ethanol
blends (16 –50% ethanol),
E85, or FlexFuel.
. Fuel with any amount of
methanol, methylal, and
aniline. These fuels can
corrode metal fuel system
parts or damage plastic and
rubber parts.
. Fuel containing metals such
as methylcyclopentadienyl
manganese tricarbonyl
(Continued)
Caution (Continued)
(MMT), which can damage
the emissions control system
and spark plugs.
. Fuel with a posted octane
rating of less than the
recommended fuel. Using this
fuel will lower fuel economy
and performance, and may
decrease the life of the
emissions catalyst.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that meet
California specifications. See the
underhood emission control label.
If this fuel is not available in states
adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting federal
specifications, but emission control
system performance may be affected.
The malfunction indicator lamp could
turn on and the vehicle may not pass a smog-check test. See
Malfunction
Indicator Lamp (Check Engine Light)
0 143. If this occurs, return to your
authorized dealer for diagnosis. If it is
determined that the condition is
caused by the type of fuel used,
repairs may not be covered by the
vehicle warranty.
Fuels in Foreign Countries
The U.S., Canada, and Mexico post
fuel octane ratings in anti-knock index
(AKI). For fuel not to use in a foreign
country, see “Prohibited Fuels” inFuel
0 286.
Fuel Additives
To keep fuel systems clean, TOP TIER
detergent gasoline is recommended.
See Fuel 0286.
If TOP TIER detergent gasoline is not
available, one bottle of GM Fuel
System Treatment Cleaner added to
the fuel tank at every engine oil
change, can help. GM Fuel System
Treatment Cleaner is the only gasoline
additive recommended by General
Motors. It is available at your dealer.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
VEHICLE CARE 309
meeting the dexos1 specification are
marked with the dexos1 approved
logo. See www.gmdexos.com.
Caution
Failure to use the recommended
engine oil or equivalent can result
in engine damage not covered by
the vehicle warranty.
Viscosity Grade
Use SAE 5W-30 viscosity grade
engine oil.
Cold Temperature Operation: In an
area of extreme cold, where the
temperature falls below −29 °C (−20 °
F), an SAE 0W-30 oil may be used. An
oil of this viscosity grade will provide
easier cold starting for the engine at
extremely low temperatures. When
selecting an oil of the appropriate viscosity grade, it is recommended to
select an oil of the correct
specification. See
“Specification”
earlier in this section.
Engine Oil Additives/Engine Oil
Flushes
Do not add anything to the oil. The
recommended oils meeting the dexos1
specification are all that is needed for
good performance and engine
protection.
Engine oil system flushes are not
recommended and could cause engine
damage not covered by the vehicle
warranty.
What to Do with Used Oil
Used engine oil contains certain
elements that can be unhealthy for
your skin and could even cause
cancer. Do not let used oil stay on
your skin for very long. Clean your
skin and nails with soap and water,
or a good hand cleaner. Wash or
properly dispose of clothing or rags
containing used engine oil. See the
manufacturer's warnings about the
use and disposal of oil products. Used oil can be a threat to the
environment. If you change your own
oil, be sure to drain all the oil from
the filter before disposal. Never
dispose of oil by putting it in the trash
or pouring it on the ground, into
sewers, or into streams or bodies of
water. Recycle it by taking it to a place
that collects used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system
that indicates when to change the
engine oil and filter. This is based on a
combination of factors which include
engine revolutions, engine
temperature, and miles driven. Based
on driving conditions, the mileage at
which an oil change is indicated can
vary considerably. For the oil life
system to work properly, the system
must be reset every time the oil is
changed.
When the system has calculated that
oil life has been diminished, it
indicates that an oil change is
necessary. A CHANGE ENGINE OIL
SOON message comes on. Change the

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
436 INDEX
Frequency StatementRadio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417
Front Pedestrian Braking (FPB) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
Front Seats Heated and Ventilated . . . . . . . . . . . . . 72
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Additives . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Economy Driving . . . . . . . . . . . . . . . . . . . 32
Filling a Portable FuelContainer . . . . . . . . . . . . . . . . . . . . . . . . 290
Filling the Tank . . . . . . . . . . . . . . . . . . . 288
Foreign Countries . . . . . . . . . . . . . . . . . 287
Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Low Fuel Warning Light . . . . . . . . . 150
Requirements, California . . . . . . . . . 287
Fuses Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Fuses and Circuit Breakers . . . . . . . 331
Instrument Panel Fuse Block . . . . 335
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
G
Garage Door Opener . . . . . . . . . . . . . . . . 179Programming . . . . . . . . . . . . . . . . . . . . . . 179
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . 328 Gauges
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Boost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Engine Coolant Temperature . . . . 139
Engine Oil Pressure . . . . . . . . . . . . . . . 137
Engine Oil Temperature . . . . . . . . . . 138
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Power Indicator . . . . . . . . . . . . . . . . . . . 136
Speedometer . . . . . . . . . . . . . . . . . . . . . . 134
Tachometer . . . . . . . . . . . . . . . . . . . . . . . 134
Trip Odometer . . . . . . . . . . . . . . . . . . . . 134
Voltmeter . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Warning Lights and
Indicators . . . . . . . . . . . . . . . . . . . . . . . . 126
General Information
Service and Maintenance . . . . . . . . 388
Towing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . 297
Glove Box . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
H
Hazard Warning Flashers . . . . . . . . . . 186
Head Restraints . . . . . . . . . . . . . . . . . . . . . . 65
Head-up Display . . . . . . . . . . . . . . . . . . . . 165
Headlamps Aiming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Automatic . . . . . . . . . . . . . . . . . . . . . . . . . 185
Bulb Replacement . . . . . . . . . . . . . . . . 330 Headlamps (cont'd)
Daytime Running
Lamps (DRL) . . . . . . . . . . . . . . . . . . . . 185
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . 185
High-Beam On Light . . . . . . . . . . . . . . 151
High/Low Beam Changer . . . . . . . . . 185
Lamps On Reminder . . . . . . . . . . . . . . 151
Heated Steering Wheel . . . . . . . . . . . . . . . . . . . . 119
Heated and Ventilated Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Heated and Ventilated Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . 55
Heater
Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Heating . . . . . . . . . . . . . . . . . . . . . . . . .191, 197
High Voltage Battery Gauge . . . . . . . 135
High-Beam On Light . . . . . . . . . . . . . . . . 151
High-Speed Operation . . . . . . . . . . . . . . 349
Hill and Mountain Roads . . . . . . . . . . 211
Hill Start Assist (HSA) . . . . . . . . . . . . . 237
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
How to Wear Seat Belts Properly . . . 79
HVAC . . . . . . . . . . . . . . . . . . . . . . . . . . .191, 197