Hummer 2007 H3 - Manual (Page 324)

When to Add Engine Oil
If the oil is below the cross-hatched area (L),
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 422.
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 322 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.
Push the dipstick all the way back in when
you are through.
324