1997 Buick Skylark Owner's Manual - Page 251

I RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS FOR BEST FUEL ECONOMY AND COLDSTARTING,SELECTTHE LOWEST SAE VISCOSITY GRADE OIL FOR THE EXPECTED TEMPERATURE RANGE. As shown in the chart, SAE 5W-30 is best for your vehicle. However, you can use SAE 1OW-30 if it's going to be0"F (- 18" C) or above. These numbers on an oil container show its viscosity, or thickness. not use Do other viscosity oils, such as 20W-50. SAE HOT WEATHER - 7 "F I 100 . LOOK FOR THIS SYMBOL NOTICE: 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. If you are inan area where the temperature falls below -20°F (-29"C), consider using either an SAE 5W-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. + 8a + 60 + 40 + 20 0 d / i COLD d WEATHER I "C + 38 + 27 + 16 +4 -7 - 18 SAE CW-30 PREFERRED DO NOT USE SAE 2OW-50 OR ANYOTHER GRADE OIL NOT RECOMMENDED 6-16