Hummer 2009 H3 Owner's Manual page 250

5-14 Service and Appearance Care
When to Add Engine Oil
If the oil is below the cross-hatched
area (L), 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 5-96.
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 5-10 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 you are through.
What Kind of Engine Oil to Use
Look for three things: