1997 Buick Century Owner's Manual - Page 269

Adding Equipment to the Outside of Your Vehicle Things you might add to the outside of your vehicle can affect the airflow around it. This may cause wind noise and affect windshield washer performance. Check with your Buick dealer before adding equipment to the outside of your vehicle. If you're using fuel ratedat 87 octane orhigher and you hear heavy knocking, your engine needs service. But don't worry if you hear a littlepinging noise when you're accelerating or driving a hill. That's normal, up to and you don't have to buy a higher octane fuel get rid of pinging. It's the heavy, constant knock that means you have a problem. If your vehicle is certified to meet California Emission Standards (indicatedon the underhood emission control label), it is designed to operate on fuels that meet California specifications.If such fuels arenot available in states adopting California emissions standards, your vehicle will operate satisfactorily on fuels meeting federal specifications, but emission control system performance may be affected. The malfunction indicator lamp on your instrument panel may turn on and/or your vehicle may fail asmog-check test. If this occurs, return to your authorized Buick dealer for diagnosis to determine the cause of failure. In the event it is determined that the cause of the conditionis the type of fuels used, repairs may not be covered by your warranty. Fuel Use regular unleaded gasoline ratedat 87 octane or higher. At a minimum, it should meet specifications ASTM D4814 in the United States and CGSB 3.5-M93 in Canada. Improved gasoline specificationshave been developed by the American Automobile Manufacturers Association (AAMA) for better vehicle performance and engine protection. Gasolines meeting the AAMA specification could provide improved driveability and emission control system protection compared to other gasolines. 87. Be sure the posted octane is at least If the octane is less than 87, you may get aheavy knocking noise when you drive. If it's bad enough, itcan damage your engine. 6-3