1995 Pontiac Sunfire Owner's Manual - Page 207

You should keepa record with all parts receiptsand list the mileage and the date of any service workyou perform. See "MaintenanceRecord" in the Index. Fuel Use regular unleaded gasoline rated at 87 octane or higher. It shouldmeet specifications ASTM D4814 in the United States and CGSB 3.5-92 in Canada. These fuels should have the proper additives, so you should not have to add anything to the fuel. In the United States and Canada, it's easy to be sure you get the right kind of gasoline (unleaded). You'll see UNLEADED righton the pump. And only unleaded nozzles will fit into your vehicle's filler neck. 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 badenough, it can damage your engine. If you're using fuel rated at 87octane or higher and you still hear heavy knocking, your engine needs service. But don't worry if you hear a little pinging noise when you're accelerating or driving up a hill. That's normal, 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. NOTICE: ~ If you try to do your own service work without knowing enough about it, your vehicle could be damaged. 6-2