2020 GMC YUKON fuel

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
220 Driving and Operating
Shifting into 4nwill turn Traction
Control and StabiliTrak/Electronic
Stability Control off. See Traction
Control/Electronic Stability Control
0 226.
Two Speed Automatic
Transfer Case
If equipped, use the transfer case
knob next to the steering wheel to
shift into and out of four-wheel drive.
All of the lights will blink on then off
momentarily when the ignition
turned on. The light that remains on
will indicate the state of the
transfer case. If the indicator mark on the switch
does not match up with the light
then that likely means the switch
was moved when the ignition
was off.
The indicator mark on the switch
must line up with the indicator light
before a shift can be commanded.
To command a shift rotate the
transfer case switch to the new
desired position. The light will blink
meaning that the shift is in progress.
When the shift is completed the new
position will be illuminated. If the
transfer case cannot complete a
shift command, it will go back to its
last chosen setting.
The settings are:
N (Neutral) :
Use only when the
vehicle needs to be towed. See
Recreational Vehicle Towing 0364
or
Towing the Vehicle 0363.
2
m(Two-Wheel Drive High) : Use
for driving on most streets and
highways. The front axle is not
engaged. This setting provides the
best fuel economy. AUTO (Automatic Four-Wheel
Drive) :
Use when road surface
traction conditions are variable.
When driving in AUTO, the front
axle is engaged, and the vehicle's
power is sent to the front and rear
wheels automatically based on
driving conditions. This setting
provides slightly lower fuel economy
than 2
m.
Do not use AUTO mode,
if equipped, to park on a steep
grade with poor traction such as ice,
snow, mud, or gravel. In AUTO
mode only the rear wheels will hold
the vehicle from sliding when
parked. If parking on a steep grade,
use 4
mto keep all four wheels
engaged.
4
m(Four-Wheel Drive High) : Use
this position when extra traction is
needed, such as when driving on
snowy or icy roads, when
off-roading, or when plowing snow.
4
n(Four-Wheel Drive Low) : This
setting engages the front axle and
delivers extra torque. Choose 4
n

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 223
Single Speed Automatic
Transfer Case
Use the transfer case knob, next to
the steering wheel, to shift into and
out of four-wheel drive for extra
traction.
All of the lights will blink on then off
momentarily when the ignition is
turned on. The light that remains on
will indicate the state of the
transfer case.If the indicator mark on the switch
does not match up with the light
then that likely means the switch
was moved when the ignition
was off.
The indicator mark on the switch
must line up with the indicator light
before a shift can be commanded.
To command a shift rotate the
transfer case switch to the new
desired position. The light will blink
meaning that the shift is in progress.
When the shift is completed the new
position will be illuminated. If the
transfer case can not complete a
shift command, it will go back to its
last chosen setting.
The settings are:
2
m(Two-Wheel Drive High) :
Use
for driving on most streets and
highways. The front axle is not
engaged. This setting provides the
best fuel economy. AUTO (Automatic Four-Wheel
Drive) :
Use when road surface
traction conditions are variable.
When driving in AUTO, the front
axle is engaged, and the vehicle's
power is sent to the front and rear
wheels automatically based on
driving conditions. This setting
provides slightly lower fuel economy
than 2
m.
Do not use AUTO mode to park on
a steep grade with poor traction
such as ice, snow, mud, or gravel.
In AUTO mode only rear wheels will
hold the vehicle from sliding when
parked. If parking on a steep grade,
use 4
mto keep all four wheels
engaged.
4
m(Four-Wheel Drive High) : Use
this position when extra traction is
needed, such as when driving on
snowy or icy roads, when
off-roading, or when plowing snow.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
254 Driving and Operating
Fuel
Top Tier Fuel
GM recommends the use of TOP
TIER Detergent Gasoline to keep
the engine clean, reduce engine
deposits, and maintain optimal
vehicle performance. Look for the
TOP TIER Logo or see
www.toptiergas.com for a list of TOP
TIER Detergent Gasoline marketers
and applicable countries.
Recommended Fuel
(L83 5.3L V8 Engine)
If the vehicle has a yellow sticker on
the fuel door, E85 or FlexFuel can
be used. If the vehicle does not
have a yellow sticker, do not use
gasoline with ethanol levels greater
than 15% by volume. SeeE85 or
FlexFuel 0255.
Use regular unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 87 —
(R+M)/2 —or higher. Do not use
gasoline with a posted octane rating
of less than 87, as this may cause
engine knock and will lower fuel
economy.
Recommended Fuel
(L86 6.2L V8 Engine)
Premium unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 93 —
(R+M)/2 —is highly recommended
for best performance and fuel
economy. Unleaded gasoline with
an octane rated as low as 87 can be
used. Using unleaded gasoline
rated below 93 octane, however, will
lead to reduced acceleration and
fuel economy. If knocking occurs,
use a gasoline rated at 93 octane
as soon as possible, otherwise, the
engine could be damaged. If heavy
knocking is heard when using
gasoline with a 93 octane rating, the
engine needs service.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 255
Do not use any fuel labeled E85 or
FlexFuel. Do not use gasoline with
ethanol levels greater than 15% by
volume.
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 that 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,
ferrocene, and aniline.
These fuels can corrode
metal fuel system parts or
damage plastic and rubber
parts.
(Continued)
Caution (Continued)
.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 0255.
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.
E85 or FlexFuel
Vehicles with a yellow fuel sticker
on the fuel door can use either
unleaded gasoline or fuel containing
up to 85% ethanol (E85). All other
vehicles should use only the
unleaded gasoline as described in
Recommended Fuel (L83 5.3L
V8 Engine) 0254 or
Recommended Fuel (L86 6.2L
V8 Engine) 0254.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
256 Driving and Operating
The use of E85 or FlexFuel is
encouraged when the vehicle is
designed to use it. E85 or FlexFuel
is made from renewable sources.
To help locate fuel stations that
carry E85 or FlexFuel, the U.S.
Department of Energy has an
alternative fuel website. See
www.afdc.energy.gov/afdc/locator/
stations.
E85 or FlexFuel should meet ASTM
Specification D 5798 or CAN/
CGSB–3.512 in Canada. Do not use
the fuel if the ethanol content is
greater than 85%. Fuel mixtures that
do not meet ASTM or CGSB
specifications can affect driveability
and could cause the malfunction
indicator lamp to come on.
The starting characteristics of E85
or FlexFuel make it unsuitable for
use when temperatures fall below
−18 °C (0 °F). Use gasoline or add
gasoline to the E85 or FlexFuel.Because E85 or FlexFuel has less
energy per liter (gallon) than
gasoline, the vehicle will need to be
refilled more often. See
Filling the
Tank 0256.
The only GM approved aftermarket
additive is ACDelco Fuel System
Treatment Plus-FlexFuel. Follow the
instructions on the bottle for proper
use. This product is available at
your GM dealer.
Caution
Some additives are not
compatible with E85 or FlexFuel
and can harm the vehicle's fuel
system. Use only additives
approved by GM for E85 or
FlexFuel vehicles. Damage
caused by unapproved additives
would not be covered by the
vehicle warranty.
Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
That damage would not be
covered under the vehicle
warranty.
To help keep the engine running
efficiently, fill the tank with gasoline,
up to E15, after filling the tank with
E85 one or two times.
Filling the Tank
An arrow on the fuel gauge
indicates which side of the vehicle
the fuel door is on. See Fuel Gauge
0 130.
{Warning
Fuel vapors and fuel fires burn
violently and can cause injury or
death.
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 257
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 re-enter the vehicle
while pumping fuel.
. Keep children away from
the fuel pump and never let
children pump fuel.
(Continued)
Warning (Continued)
.Before touching the fill
nozzle, touch a metallic
object to discharge static
electricity from your body.
. Fuel can spray out if the fill
nozzle is inserted too
quickly. This spray can
happen if the tank is nearly
full, and is more likely in hot
weather. Insert the fill nozzle
slowly and wait for any hiss
noise to stop before
beginning to flow fuel.
To open the fuel door, push and
release the rearward center edge of
the door.
The capless refueling system does
not have a fuel cap. Fully insert and
latch the fill nozzle, then begin
fueling.
{Warning
Overfilling the fuel tank by more
than three clicks of a standard fill
nozzle may cause:
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
258 Driving and Operating
Warning (Continued)
.Vehicle performance issues,
including engine stalling and
damage to the fuel system.
. Fuel spills.
. Under certain conditions,
fuel fires.
Be careful not to spill fuel. Wait
five seconds after you have finished
pumping before removing the fill
nozzle. Clean fuel from painted
surfaces as soon as possible. See
Exterior Care 0367. Push the fuel
door closed until it latches.
{Warning
If a fire starts while you are
refueling, do not remove the fill
nozzle. Shut off the flow of fuel by
shutting off the pump or by
notifying the station attendant.
Leave the area immediately. Filling the Tank with a Portable
Fuel Container
If the vehicle runs out of fuel and
must be filled from a portable fuel
container:
1. Locate the capless funnel
adapter.
2. Insert and latch the funnel into the capless fuel system.
{Warning
Attempting to refuel from a
portable fuel container without
using the funnel adapter may
cause fuel spillage and damage
the capless fuel system. This
could cause a fire. You or others
could be badly burned and the
vehicle could be damaged. 3. Remove and clean the funnel
adapter and return it to the
storage location.
Filling a Portable Fuel
Container
{Warning
Never fill a portable fuel container
while it is in the vehicle. Static
electricity discharge from the
container can ignite the fuel
vapor. You or others could be
badly burned and the vehicle
could be damaged. To help avoid
injury to you and others:
. Dispense fuel only into
approved containers.
. Do not fill a container while
it is inside a vehicle, in a
vehicle's trunk, in a pickup
bed, or on any surface other
than the ground.
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 259
Warning (Continued)
.Bring the fill nozzle in
contact with the inside of
the fill opening before
operating the nozzle.
Maintain contact until filling
is complete.
. Keep sparks, flames, and
smoking materials away
from fuel.
. Do not use electronic
devices while pumping fuel.
Trailer Towing
General Towing
Information
Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle to tow a trailer. Read the
entire section before towing a trailer.
To tow a disabled vehicle, see
Towing the Vehicle 0363. To tow
the vehicle behind another vehicle
such as a motor home, see
Recreational Vehicle Towing 0364.
Driving Characteristics
and Towing Tips
{Warning
You can lose control when towing
a trailer if the correct equipment is
not used or the vehicle is not
driven properly. For example,
if the trailer is too heavy or the
(Continued)
Warning (Continued)
trailer brakes are inadequate for
the load, the vehicle may not stop
as expected. You and others
could be seriously injured. The
vehicle may also be damaged,
and the repairs would not be
covered by the vehicle warranty.
Pull a trailer only if all the steps in
this section have been followed.
Ask your dealer for advice and
information about towing a trailer
with the vehicle.
Driving with a Trailer
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to be
used properly.
The following information has many
time-tested, important trailering tips
and safety rules. Many of these are