Buick Enclave Owner's Manual page 270

See
for the location of the
engine oil fill cap.
Add enough oil to put the level
somewhere in the proper operating
range. Push the dipstick all the way
back in when through.
Selecting the right engine oil
depends on both the proper oil
specification and viscosity grade.
See
Use and ask for licensed engine oils
with the dexos1
certification mark. Engine oils
meeting the requirements for the
vehicle should have the dexos1
approved certification mark. This
certification mark indicates that the
oil has been approved to the dexos1
specification.
.
®
approved
SAE 5W-30 is the best viscosity
grade for the vehicle. Do not use
other viscosity grade oils such as
SAE 10W-30, 10W-40, or 20W-50.
Cold Temperature Operation: In an
area of extreme cold, where the
temperature falls below 29°C
( 20°F), an SAE 0W-30 oil may be
used. An oil of this viscosity grade
will provide easier cold starting for
the engine at extremely low
temperatures. When selecting an oil
of the appropriate viscosity grade,
always select an oil of the correct
specification. See Specification
earlier in this section for more
information.
Do not add anything to the oil. The
recommended oils with the dexos
specification and displaying the
dexos certification mark are all that
is needed for good performance and
engine protection.