1996 Pontiac Bonneville Owner's Manual - Page 260

I I RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST SAE VISCOSITY GRADE OIL FOR THEEXPECTEDTEMPERATURERANGE. 1 HOT WEATHER / WOK FOR THIS SYMBOL 4 As shown.inthe chart,SAE 1OW-30 is best for your vehicle. However,you can useSAE 5W-30 if it's going to be colder than O (16 C) before your next oil 60 F change. When it's very cold, you should S A E use 5W-30. These numbers on oil container show its an viscosity, or thickness. Do not use other viscosity oils, such as SAE 20W-50. O NOTICE: Use only engineoil 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. SAE 10W-30 PREFEMEO abow (PF SAE 5W-30 \ (-18°C) GM Goodwrench@ meets all the requirements for oil your vehicle. Engine Oil Additives COLD I WEATHER DO NOT USE SAE MW-50 OR ANY OTHER GRADE OIL NOT RECOMMENDED Don't add anything to your oil. Pontiac dealer Your is ready to advise if you something should be added. think 6-15