1994 GMC Sonoma Owner's Manual - Page 227

Engine Oil Turn off the engine and give the oil few a minutes to drainback into the oil pan. If you don't, the oil dipstick might not show the actual level. To Check Engine Oil Pull out the dipstickand clean itwith a paper towel or cloth,then push it back in all theway. Remove it again, keeping the tiplower. 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 section explains what kind of oil touse. For crankcase capacity, see "Capacitiesand Specifications" in the Index. 6-9