1997 GMC Savana Van Owner's Manual - Page 249

I RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST SAE VISCOSITY GRADE OIL FOR THEEXPECTEDTEMPERATURERANGE. As shown in the chart, SAE 5W-30 is best for your vehicle. However, you can use SAE low-30 if it's going to be 0°F (- 18"C) or above. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils, such as SAE 20W-50. I HOT WEATHER +loo+ 80+60- 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. ~ - - +40- - +20- -- 7 0 - - -18 -SAE 5W1 - 3 0 PREFERREO ~ GM Goodwrench@, meets all therequirements for oil 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 an SAE OW-30 oil. Both will provide easier cold starting and better protection for your engine at extremely lowtemperatures. DONOTUSE SAE 2OW-50 OR ANYOTHER GRADE OIL NOT RECOMMENDED COLD WEATHER L 6-15