2007 Buick LaCrosse Owner's Manual - Page 354

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 350 for the location of the engine oil fill cap. 3.6L V6 Engine 3.8L V6 Engine If the oil is below the cross-hatched area at the tip of the dipstick, you will need to add at least one quart/liter of oil. But you must use the right kind. This section explains what kind of oil to use. For engine oil crankcase capacity, see Capacities and Specifications on page 454. Be sure to 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. 354