GMC 1994 Yukon Owner's Manual page 269

When to Add Oil
If the oil is at or below the ADD line, then
YOU' ^ ^
need to add some oil. But
you must use the right kind. This section explains what kind of oil to use.
For crankcase capacity, see "Capacities and Specifications" in the Index.
NOTICE:
Don't add too much oil. If your engine has so much oil that the
oil level gets above the proper operating range, your engine
could be damaged.
The engine oil filler
cap is located on a
filler tube at the front
of the engine.
Just fill it enough to put the level somewhere in the proper operating range.
Push the dipstick all the way back in when you're through.
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