Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
16412876) - 2023 - CRC - 3/25/22
310 Driving and Operating
Recommended Fuel
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.
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.
(Continued)
Caution (Continued)
.
Fuel with any amount of
methanol, methylal,
ferrocene, and aniline.
These fuels can 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.