GMC 1995 Safari Owner's Manual page 215

To Check Engine Oil
Pull out the dipstick and clean it with a paper towel or cloth, then push it
back in all the way. Remove it again, keeping the tip down.
When to Add Oil
If the oil is at or below the ADD line, then you'll need to add some oil. But
you must use the right kind. This part 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 cross-hatched area that shows the proper
operating range, your engine could be damaged.
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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