GMC 2007 Yukon XL Owner's Manual page 439

When to Add Engine Oil
If the oil is below the cross-hatched area at the tip
of the dipstick, you will need to add at least one
quart/liter of oil. But you must use the right
kind. This section explains what kind of oil to use.
For engine oil crankcase capacity, see Capacities
and Specifications on page 548.
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.
Be sure to add enough oil to put the level
somewhere in the proper operating range. Push
the dipstick all the way back in when you are
through.
See Engine
Compartment Overview
on page 436 for the
location of the engine oil
fill cap.
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