1997 Pontiac Grand Prix Owner's Manual - Page 287

RECOMMENDED SAE VISCOSITY GRADE ENGINE OILS FOR BEST FUEL ECONOMY AND COLD STARTING, SELECT THE LOWEST SAE VISCOSITY GNRADE OIL FOR THE EXPECTED TEMPERATURE RANGE. HOT WEATHER c "F + 100 + 80 +60- 7 LOOK FOR MIS SYMBOL As shown in thechart, if you have the 3800 engine, SAE 1OW-30 is bestfor your vehicle. However, you can use SAE 5W-30 if it's going to be colder than 60°F (16OC) before your next oil change. When it's very cold, you should use SAE 5W-30. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils, such as SAE 20W-50. "C + 38 t 27 t 16 +40 +20 - t4 -7 0- - 18 SAE 1OW-30 - PREFERRED I COLD WEATHER SAE 5W-30 above 0°F (-18%) I W NOT USE SAE 2OW-50 OR ANY OTHER GRADE OIL NOT RECOMMENDED 3800 or 3800 Supercharged Engine 6-17