1994 GMC Suburban Owner's Manual - Page 264

You should look for this on the front of the oil container, and use only oils that display this new symbol. You should also use the proper viscosity oil for your vehicle, as shown in the following chart: LIGHT DUTY EMISSIONS -GAS ENGINES 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 F + 100 '80 +60 +40 +20 ' LOOK FOR ONE OF THESE LABELS C - +38 - +27 .+16 8 ' .+4 *-7 - 0. '-18 SAE 1OW-30 SAE 5W-30 PREFERRED IF NEITHER SAE 5W-30 NOR SAE 1OW-30 GRADE OILS ARE AVAILABLE, SAE 30 GRADE MAY BE USED AT TEMPERATURES ABOVE 40 DEGREES F (4 DEGREES C). DO NOT USE SAE 1OW-40, SAE 2OW-50 OR ANY OTHER GRADE OIL NOT RECOMMENDED As shown in the chart, SAE 5W-30 is best for your vehicle. However, you can use SAE 1OW-30 if it's going to be 0°F (-I 8°C) or above. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils, such as SAE lOW-40 or SAE 20W-50. 6-18