Cadillac CTS 2011 Owner's Manual page 331

Use of Substitute Engine Oils if
dexos is unavailable: In the
event that dexos approved
engine oil is not available at an oil
change or for maintaining proper
oil level, you may use substitute
engine oil displaying the API
Starburst symbol and of
SAE 5W-30 viscosity grade. Use
of oils that do not meet the
dexos specification, however,
may result in reduced
performance under certain
circumstances.
Viscosity Grade
SAE 5W-30 is best viscosity
grade for the vehicle. Do not use
other viscosity grade oils such
as SAE 10W 30, 10W 40,
or 20W-50.
Vehicle Care
Cold Temperature Operation: In
an area of extreme cold, where
the temperature falls
below 29°C ( 20°F), an
SAE 0W-30 oil should 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, be sure to always select
an oil that meets the required
specification, dexos . See
Specification for more
information.
Engine Oil Additives/Engine
Oil Flushes
Do not add anything to the oil. The
recommended oils that meet the
dexos certification mark are all
that is needed for good performance
and engine protection.
Engine oil system flushes are not
recommended and could cause
engine damage not covered by the
vehicle warranty.
10-13