1999 Cadillac Catera Owner's Manual - Page 251

yellowblue As shown in the chart, SAE 10W-30 is best for your vehicle. However, you can use SAE 5W-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-50. _ _ 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 GoodwrenchR oil meets all the requirements for your vehicle. -20_F (-29_C), consider using either an SAE 5W-30 synthetic oil or an SAE 0W-30 oil. Both will provide If you are in an area where the temperature falls below easier cold starting and better protection for your engine at extremely low temperatures. 6-13