1997 Buick Riviera Owner's Manual - Page 240

Adding Equipment to the Outside of Your Vehicle You can be injured andyour vehicle could be damaged if you try to do service work on a vehicle without knowing enoughabout it. Be sure you have sufficient knowledge, experience, the proper replacement parts and tools before you attempt anyvehicle maintenance task. Be sure touse the proper nuts, bolts and other fasteners. "English" and "metric" fasteners canbe easily confused. If you use the wrong fasteners, parts later break can or fall off. You could behurt. Things you might add to the outsideyour vehicle can of This affect the airflow around it. may cause wind noise and affect windshield washer performance. Check with your Buick dealer before adding equipment the to outside of your vehicle. Fuel The 8th digit your vehicle identification number of (VIN) shows thecode letter for your engine.You will left find the VIN at the top of your instrument panel. (See "Vehicle Identification Number" the Index.) in If you havethe 3800 engine (VIN Code K), use regular 87 If unleaded gasoline rated at octane or higher. you're using fuel rated at the recommended octane or higher and you still hear heavy knocking, your engine needs if little pinging service. But don't worry you hear a hill. noise when you're accelerating driving up a or That's normal, and you don't have to buy a higher octane fuelto get rid of pinging. It's the heavy, constant knock that means you have a problem.