2003 Buick Century Owner's Manual - Page 232

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 any oil which does not carry this starburst symbol. If you choose to perform the engine oil change service yourself, be sure the oil you use has the starburst symbol on the front of the oil centainer. I f you have p i l r oil changed for you, be sure the oil put into your engine is American Petroleum Institute certified for gasoline engines. RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS HOT WEATHER "F 100 t 80 LOOK FOR THIS SYMBOL 1 k 60 L. t 401 0 + 20 I I L COLD t 4 I "C - 7 t38 - t27 - + 16 - t 4 --7 - - 18 SAE 5W-30 RECOMMENDED WEATHER DO NOT USE SAE IOW-40, 2OW-50 OR ANY OTHER SAE V!-CCOS!TVGRADE OIL Me? R E C O M Y E ~ D 5-15