Cadillac XT5 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
16406251) - 2023 - CRC - 3/25/22
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 resultin 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
(Continued)
Cadillac XT5 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
16406251) - 2023 - CRC - 3/25/22
Driving and Operating 319
Caution (Continued)
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.
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 Fuels0318.
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.
Filling the Tank
An arrow on the fuel gauge
indicates which side of the
vehicle the fuel door is on. See
Fuel Gauge 0125.
{Warning
Fuel vapors and fuel fires
burn violently and can cause
injury or death.
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)
