1998 Chevrolet Astro Owner's Manual - Page 265

I You can be injured and J licle could be damaged if you try to do service work on a vehicle without knowing enough about it. 0 Be sure you have sufficientknowledge, experience, the proper replacement parts and tools beforeyou attempt any vehicle maintenance task. Be sure touse the proper nuts, bolts and other fasteners. "English"and "metric" fasteners can be easily confused. you use If the wrongfasteners, parts can later break or fall off. You could behurt. 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 haw 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 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. If you're using fuel rated at 87 octane orhigher and you 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. I ! Adding Equipment to the Outside of Your Vehicle Things you might add to the outsideof your vehicle can affect the airflowaround it. This may cause wind noise and affect windshield washer performance. Check with your dealer beforeadding equipment to the outsideof your vehicle.