1998 Buick LeSabre Owner's Manual - Page 263

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. ' RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS FOR BESTFUELECONOMYANDCOLDSTARTING,SELECTTHELOWEST SAE VISCOSITY GRADE O FOR THE EXPECTED TEMPERATURE RANGE. L I I I If you change your own oil, be sureyou use oil that has the Starburst symbol on the front the of oil container. If you have your oil changed for you, be sure the oil put into your engine is American Petroleum Institutecertified for easoline engines. U U HOT WEATHER __ "c' LOOK FOR MIS SYMBOL + 38 + 27 You should also use the proper viscosity oil for your vehicle, as shown in the following chart: i ?d I < I COLD WEATHER DO NOT USE SAE 2OW-50 OR ANY OTHER GRADE OIL NOT RECOMMENDED t SAE SW-30 6-13