1998 Pontiac Firebird Owner's Manual - Page 267

When to Add Engine Oil If the oil is at or below the line, then you'll ADD need to add at least one quart of oil. Butyou must use the right kind. This part explains what kindof oil to use. Forcrankcase capacity, see "Capacities and Specifications" in the Index. What Kind of Engine Oil to Use Oils recommendedfor your vehicle can be identified by looking for the "Starburst"symbol. This symbol indicates that the oil been certified by American has the Petroleum Institute(API).Do not use any oil which does not carrythis Starburst symbol. AAAA NOTICE: Don't add too much oil. your engine has If so much oil thatthe oil level gets above the cross-hatched area that shows the proper operating range, your engine could be damaged. Be sure tofill it enough toput the level somewhere in the proper operating range. Push the dipstick all the way backin when you're through. - . v - If you change your own oil, be sure you use oil that has the Starburst symbol onthe front of the oil container. If you have your oil changed for you, be surethe oil put into your engine is American Petroleum Institute certified for gasoline engines. You should also use the proper viscosity oilfor your vehicle, as shown in the following chart: 6-14