Cadillac 2008 DTS - Manual (Page 308)

When to Add Engine Oil
If the oil is below the cross-hatched area at the tip
of the dipstick, add at least one quart/liter of the
recommended oil. This section explains what kind
of oil to use. For engine oil crankcase capacity,
see Capacities and Specifications on page 5-105.
Notice: Do not add too much oil. If the engine
has so much oil that the oil level gets above
the cross-hatched area that shows the proper
operating range, the engine could be damaged.
See Engine Compartment
Overview on page 5-12
for the location of the
engine oil fill cap.
Be sure to add enough oil to put the level somewhere
in the proper operating range in the cross-hatched area.
Push the dipstick all the way back in when you are
through.
5-14