1998 Pontiac Grand Prix Owner's Manual - Page 278

A CAUTION: You can be injured and your vehicle c! !d be damaged if you try to doservice work ona vehicle without knowing enough about it. Be sure you have sufficientknowledge, experience, the properreplacement parts and tools before you attempt anyvehicle maintenance task. Be sure touse the proper nuts, bolts and other fasteners. "English" and "metric" fasteners can be easily confused. If you use the wrong fasteners, parts can later break or fall off. You could behurt. Adding Equipment to the Outside of Your Vehicle Things you might add to outside of your vehicle can the affect the airflow around This may cause wind noise it. and affect windshield washer performance. Check with your dealer before adding equipment the outsideof to your vehicle. Fuel The 8th digitof your vehicle identification number (VIN) showsthe code letter for your engine.You will find the VIN the topleft of your instrument panel. at (See "Vehicle Identification Number" the Index.) in If you have the 3100 engine (VINCode M) o 3800 r engine (VIN CodeK),use regular unleaded gasoline fuel rated at 87 octane or higher. If you're using rated at the recommended octaneor higher and you hear heavy knocking, your engine needs service. But don't worry if you hear a little pinging noise when you're accelerating or drivingup a hill. That's normal, and you don't have fuel to buy a higher octane to get rid of pinging. It's the heavy, constant knock means you have a problem. that 6-3