Recommended Fuel; L4 Engine); V6 Engine); Prohibited Fuels - GMC XT5 2023 Owner's Manual

318 Driving and Operating

Recommended Fuel

(2.0L L4 Engine)
Premium unleaded gasoline
meeting ASTM specification
D4814 with a posted octane
rating (R+M)/2 of 91 or greater
is recommended. If unavailable,
unleaded gasoline with a
posted octane rating of
87 may be used, but will result
in reduced performance and
driveability. If heavy knocking
is heard when using gasoline
rated at 91 or greater, the
engine needs service.
Do not use any fuel labeled
E85 or FlexFuel. Do not use
gasoline with ethanol levels
greater than 15% by volume.
Recommended Fuel
(3.6L V6 Engine)
Regular unleaded gasoline
meeting ASTM specification
D4814 with a posted octane
rating (R+M)/2 of 87 or
greater is recommended. Do
not use gasoline with a posted
octane rating of less than 87,
as this will result in reduced
performance and driveability.
If heavy knocking is heard
when using gasoline rated at
87 or greater, the engine
needs service.
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
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