
Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
278 DRIVING AND OPERATING
Caution (Continued)
corrode metal fuel system
parts or damage plastic and
rubber parts.
. Fuel containing metals such
as methylcyclopentadienyl
manganese tricarbonyl
(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.
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 0277.
Fuel Additives
TOP TIER Detergent Gasoline is highly
recommended for use with your
vehicle. If your country does not have
TOP TIER Detergent Gasoline, add
ACDelco Fuel System Treatment Plus
−Gasoline to the vehicle’s gasoline fuel
tank at every oil change or 15,000 km
(9,000 mi), whichever occurs first. TOP
TIER Detergent Gasoline and ACDelco
Fuel System Treatment Plus−Gasoline
will help keep your vehicle’s engine
fuel deposit free and performing
optimally.
Filling the Tank
{Warning
Fuel vapors and fuel fires burn
violently and can cause injury or
death.
(Continued)
Warning (Continued)
Follow these guidelines:
. To help avoid injuries to you
and others, read and follow
all the instructions on the
fuel pump island.
. Turn off the engine when
refueling.
. Keep sparks, flames, and
smoking materials away
from fuel.
. Do not leave the fuel pump
unattended.
. Avoid using electronic devices
while refueling.
. Do not reenter the vehicle
while pumping fuel.
. Keep children away from the
fuel pump and never let
children pump fuel.
(Continued)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
302 VEHICLE CARE
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 dexos
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
oil as soon as possible within the next
1 000 km (600 mi). It is possible that,
if driving under the best conditions,
the oil life system might indicate that
an oil change is not necessary for up
to a year. The engine oil and filter
must be changed at least once a year
and at this time the system must be
reset. Your dealer has trained service
people who will perform this work and
reset the system. It is also important
to check the oil regularly over the
course of an oil drain interval and
keep it at the proper level.
If the system is ever reset accidentally,
the oil must be changed at 5 000 km
(3,000 mi) since the last oil change.
Remember to reset the oil life system
whenever the oil is changed.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
INDEX 429
Driving (cont'd)Vehicle Load Limits . . . . . . . . . . . . . . 197
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . 193
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
E
Electric Parking Brake . . . . . . . . . . . . . . 218
Electric Parking Brake Light . . . . . . . 143
Electrical Equipment, Add-On . . . . . 287
Electrical System
Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Fuses and Circuit Breakers . . . . . . . 322
Instrument Panel Fuse Block . . . . 330
Overload . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . 304
Check Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . . . . . 139
Compartment Overview . . . . . . . . . . 292
Coolant Temperature Gauge . . . . . 135
Coolant Temperature
Warning Light . . . . . . . . . . . . . . . . . . . 146
Cooling System . . . . . . . . . . . . . . . . . . . 307 Engine (cont'd)
Drive Belt Routing . . . . . . . . . . . . . . . . 399
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Oil Life System . . . . . . . . . . . . . . . . . . . . 302
Oil Pressure Gauge . . . . . . . . . . . . . . . . 134
Oil Pressure Light . . . . . . . . . . . . . . . . . 147
Overheating . . . . . . . . . . . . . . . . . . . . . . . 312
Power Messages . . . . . . . . . . . . . . . . . . 156
Running While Parked . . . . . . . . . . . 210
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
Engine Air Filter Life System . . . . . . 304
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . 172
Equipment, Towing . . . . . . . . . . . . . . . . . 286
Event Data Recorders . . . . . . . . . . . . . . 412
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . 172
Extended Parking . . . . . . . . . . . . . . . . . . . 209
Extender, Seat Belt . . . . . . . . . . . . . . . . . . 82
Exterior Lamp Controls . . . . . . . . . . . . 166
Exterior Lamps Off Reminder . . . . . . 168
Exterior Lighting Battery Saver . . . . 173
F
Features Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Filter, Engine Air Cleaner . . . . . . . . . . . . . . . . 304 Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . 168
Flashers, Hazard Warning . . . . . . . . . . 169
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
Changing . . . . . . . . . . . . . . . . . . . . . . . . . . 361
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
Fluid Automatic Transmission . . . . . . . . . 303
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
Folding Mirrors . . . . . . . . . . . . . . . . . . . . . . 53
Forward Automatic Braking . . . . . . . . 264
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Frequency Statement Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
Front Pedestrian Braking (FPB)
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Front Seats Heated and Ventilated . . . . . . . . . . . . . 70
Fuel Additives . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Economy Driving . . . . . . . . . . . . . . . . . . . 27
Filling a Portable Fuel
Container . . . . . . . . . . . . . . . . . . . . . . . . 280
Filling the Tank . . . . . . . . . . . . . . . . . . . 278
Foreign Countries . . . . . . . . . . . . . . . . . 278
Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Low Fuel Warning Light . . . . . . . . . 148