2003 Buick LeSabre Owner's Manual - Page 267

What Kind of Engine Oil to Use Oils recommended for your vehicle can be identified by looking for the starburst symbol. This symbol indicates that the oil has been certified by the American Petroleum Institute (API). Do not use any oil which does not carry this starburst symbol. If you choose to perform the engine oil change service yourself, be sure the oil you use hasthe starburst symbol onthe front of the oil container. If you have your changed oil for you, besure the oil put into you engine is American Petroleum Institute certified for gasoline engines. I I I I RECOMMENOEO VISCOSITY SAE GRADE ENGINE OILS FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST SAEVISCOSITY GRADE O FOR THE EXPECTEDTEMPERATURE RANGE. I L I I I HOT WEATHER You should also use the proper viscosity oil for yout vehicle, as shown in the viscosity chart. SAE 1OW-30 is the viscosity grade recommended for your vehicle. However, youcan use SAE 5W-30 if it's going to be colder than 60°F (16°C) before your next oil change. Whenit isvery cold, colder than 0°F (-18"C), you should use an SAE 5W-30 oil. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity grade oils, suchas SAE 1OW-40 or SAE 20W-50 under any conditions. 5-16 COLD WEATHER DO NOT USE SAE ZUW-50 OR ANY OTHER GRADE OIL NOT RECOMMENDED I I I