2009 Buick LaCrosse Owner's Manual - Page 286

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 cross-hatched area that shows the proper operating range, the engine could be damaged. See Engine Compartment Overview on page 5-12 for the location of the engine oil fill cap. 3.8L V6 Engine 5.3L V8 Engine If the oil is below the cross-hatched area at the tip of the dipstick, 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 5-106. Add enough oil to put the level somewhere in the proper operating range in the cross-hatched area. Push the dipstick all the way back in when you are through. 5-16