1998 Oldsmobile Achieva Owner's Manual - Page 231

Fuel You can be injured and your vehicle could be damaged if you try to do service workon a vehicle without knowing enoughabout it. Be sure you have sufficient knowledge, experience, the proper replacement parts and tools beforeyou attempt any vehicle maintenance task. Be sure to use 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. Use regular unleaded gasoline ratedat 87 octane or higher. At aminimum, it shouldmeet 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 controlsystem protection compared to other gasolines. Be surethe 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. If you're using fuel rated at 87 octane or higher you and 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 and you don't have to buy a higher octane fuel to get rid of pinging. It's the heavy, constant knock that means you have a problem. 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 retailer beforeadding equipment to the outside of your vehicle. 6-3