GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-14632286) - 2021 - CRC - 11/19/20
270
Driving and Operating
Recommended Fuel
For diesel engine vehicles, see
“
Fuel for
Diesel Engines
”
in the Duramax diesel
supplement.
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. See
.
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.
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
.
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
