1997 Chevrolet Astro Owner's Manual - Page 269

RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST S E VISCOSITY GRADE OIL FOR THE EXPECTED TEMPERATURE RANGE. A As shown in the chart, SAE 5W-30 is best for your vehicle. However, you can use SAE 1OW-30 if it's going numbers on an oil to be 0°F (-18°C) or above. These container show its viscosity, or thickness. Do not use other viscosity oils, such as SAE 20W-50. HOT WEATHER 7 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 in an area where the temperature falls below -20°F (-29"C), consider using either an SAE 5W-30 synthetic oil or SAE OW-30 oil. Both will provide an easier cold starting better protection for your engine and at extremely low temperatures. "F c 100 - "C t 38 t 21 t 16 +80. +60. +40. +20. 0- t b -7 - 18 I COLD WEATHM DO NOT USE SAE 2OW-50 OR ANYOTHER GRADE OIL NOT RECOMMENDED 6-13