2009 Pontiac G6 Owner's Manual - Page 260

When to Add Engine Oil Notice: Do not add too much oil. If the engine has so much oil that the oil level gets above the upper mark that shows the proper operating range, the engine could be damaged. See Engine Compartment Overview on page 5-14 for the location of the engine oil fill cap. L4 Engine V6 Engine If the oil is below the MIN mark for the L4 engine or below the cross-hatched area at the tip of the dipstick for the V6 engine, 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 5-118. 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. 5-22