1996 GMC Sonoma Owner's Manual - Page 234

What Kind of 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 BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST SAE VISCOSITY GRADE OIL FOR THE EXPECTED TEMPERATURE RANGE. HOT WEATHER "( + 38 8 + Z1 7 t 16 r4 -7 -1 I f you change your own oil. be sure you use oil that has the Starburst symbol on the front of the oil container. If you have your oil changed for you, be sure the oil put into your engine is American Petroleum Institute certifiecl for gasoline engines. SAE CW-30 PREFERRED I WEATHER DO NOT USE SAE 2OW-50 OR ANY OTHER GRADE OIL NOT RECOMMENDED You should also use the proper viscosity oil for your vehicle, as shown in the following chart: 6-12