Cadillac 2011 CTS Coupe Owner's Manual page 335

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 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.
Engine oil system flushes are not
recommended and could cause
engine damage not covered by the
vehicle warranty.
Used engine oil contains certain
elements that can be unhealthy for
your skin and could even cause
cancer. Do not let used oil stay on
your skin for very long. Clean your
skin and nails with soap and water,
or a good hand cleaner. Wash or
properly dispose of clothing or rags
containing used engine oil. See the
manufacturer's warnings about the
use and disposal of oil products.
Used oil can be a threat to the
environment. If you change your
own oil, be sure to drain all the oil
from the filter before disposal. Never
dispose of oil by putting it in the
trash or pouring it on the ground,
into sewers, or into streams or
bodies of water. Recycle it by taking
it to a place that collects used oil.