1997 Buick LeSabre Owner's Manual - Page 260

RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS . FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST SAE VISCOSITY GRADE OIL FOR THE EXPECTED TEMPERATURE RANGE. HOT WEATHER As shown in the chart, SAE low-30 is best for your vehicle. However, you can use SAE SW-30 if it's going to be colder than 60°F ( 16"C) before your next oil change. When it's very cold, you should use SAE 5W-30. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils, such as SAE 20W-SO. NOTICE: t 80- - +27 t 60 :--- + 16 +40--+4 t20---7 0----18 Use only engine oil with the American Petroleum Institute Certified For Gasoline Engines "Starburst" symbol. Failure to use the recommended oil can result in engine damage not covered by your warranty. GM Goodwrench@oil meets all the requirements for your vehicle. SAE 5W-30 . -- - I , COLD WEATHER DO NOT USE SAE 2OW-50OR ANY OTHER GRADE OIL NOT RECOMMENDED If you are in an area where the temperature falls below -20°F (-29"C), consider using either an SAE SW-30 synthetic oil or an SAE OW-30 oil. Both will provide easier cold starting and better protection for your engine at extremely low temperatures. 6-12