1998 Oldsmobile Aurora Owner's Manual - Page 264

NOTICE: Don't add too much oil. your engine has If so much oil that the oil level gets above the upper mark that shows the proper operating range, your engine could be damaged. Be sure to fill it enough to put the levelsomewhere in the proper operating range. Push the dipstickall the way back in when you're through. What Kind of Engine Oil to Use Oils recommended for your vehicle can be identified by looking for the"Starburst" symbol. This symbol indicates that the oil has been certified by the American Petroleum Institute (API). Do not use anyoil which does not carry this Starburstsymbol. If you change your own oil, be sureyou 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 into put your engine is American Petroleum Institute certified for gasolineengines. You should also use the proper viscosity oil foryour vehicle, as shown in the following chart: 6-12