1995 Buick Century Owner's Manual - Page 213

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 explainswhat kind of oil to use. For crankcase capacity, see "Capacities and Specifications" in the Index. What Kind of Oil to Use Oils of the proper quality for your vehicle can be identified by looking for the "Starburst" symbol. The "Starburst" symbol indicates that the oil has been certified by the American Petroleum Institute (API), and is preferredfor use in your gasoline engine. 1 NOTICE: Don't addtoo 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. If you change your own oil, be sure you use oil that has the "Starburst" symbol on the front of the oil container. If you have your oil changed for you, be sure the oil put into your engine is American Petroleum Institute certified for gasoline engines. You should also use the proper viscosity oil for your vehicle, as shown in the following chart: 6-9