Owner’s Manual

Black plate (71,1)
GMC Yukon/Yukon XL Owner Manual - 2011
Driving and Operating 9-71
Many service stations will not
have an 85% ethanol fuel (E85)
pump available. The U.S.
Department of Energy has
an alternative fuels website
(www.afdc.energy.gov/afdc/locator/
stations/) that can help you find
E85 fuel. Those stations that do
have E85 should have a label
indicating ethanol content. Do not
use the fuel if the ethanol content is
greater than 85%.
At a minimum, E85 should meet
ASTM Specification D 5798. By
definition, this means that fuel
labeled E85 will have an ethanol
content between 70% and 85%.
Filling the fuel tank with fuel
mixtures that do not meet ASTM
specifications can affect driveability
and could cause the malfunction
indicator lamp to come on.
To ensure quick starts in the
wintertime, the E85 fuel must be
formulated properly for your climate
according to ASTM specification
D 5798. If you have trouble starting
on E85, it could be because the
E85 fuel is not properly formulated
for your climate. If this happens,
switching to gasoline or adding
gasoline to the fuel tank can
improve starting. For good starting
and heater efficiency below 0°C
(32°F), the fuel mix in the fuel
tank should contain no more than
70% ethanol. It is best not to
alternate repeatedly between
gasoline and E85. If you do switch
fuels, it is recommended that you
add as much fuel as possible — do
not add less than 11 L (3 gal) when
refueling. You should drive the
vehicle immediately after refueling
for at least 11 km (7 mi) to allow the
vehicle to adapt to the change in
ethanol concentration.
E85 has less energy per liter
(gallon) than gasoline, so you will
need to refill the fuel tank more
often when using E85 than when
you are using gasoline. See Filling
the Tank on page 9‑72.
Notice: Some additives are not
compatible with E85 fuel and can
harm the vehicle's fuel system.
Do not add anything to E85.
Damage caused by additives
would not be covered by the
vehicle warranty.
Notice: This vehicle was not
designed for fuel that contains
methanol. 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.