1997 Buick LeSabre Owner's Manual - Page 251

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. Checkwith your Buick dealer before adding equipment to the outside of your vehicle. If you're using fuel rated at 87 octane or higher and you still hear heavy knocking, your engineneeds service. But don'tworry if you hear a little pinging noise when you're accelerating or driving a hill. That's normal, up and you don't have to buy a higher octane fuel to get rid of pinging. It's the heavy, constant knockthat means you have a problem. If your vehicle is certifiedto meet CaliforniaEmission Standards (indicated on the underhood tune-up label), it is designed to operateon fuels that meet California specifications. If such fuels are not available states in 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 instrumentpanel may turn on and/or your vehicle may fail a smog-check test. If this occurs, return to your to authorized Buick dealer for diagnosis determine the cause of failure. In the event it is determined that the cause of the condition is the type of fuels used, repairs may not be covered by your warranty. Fuel Use regular unleaded gasoline rated at 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 specifications have been developed by the American Automobile Manufacturers Association (AAMA) forbetter vehicle performance and engineprotection. Gasolines meetingthe AAMA specification could provide improved driveability and emission control system protection compared to other gasolines. Be sure the posted octane is at least 87. If the octane is less than 87, you may get a heavy knocking noise when you drive. If it's bad enough, it can damage your engine. 6-3