1998 Chevrolet Blazer Owner's Manual - Page 273

/!\ CAUTION: You can be injured and your vehicle could be damaged if you try to do service work on a vehicle without knowing enoughabout it. Be sure you have sufficient knowledge, experience, the proper replacement parts and tools before youattempt 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 be hurt. Use regular unleadedgasoline rated at 87 octane or higher. At a minimum, it should meet specifications ASTM D48 14 in United States and CGSB 3.5-M93 the in Canada. Improved gasoline specifications have been developed by the American Automobile Manufacturers Association (AAMA) for better vehicle performance and engine protection. Gasolines meeting the AAMAspecification 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 geta heavy knocking noise when you drive. If it's bad enough, it can damage yourengine. If you're using fuel rated at 87 octane or higher 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 haveto buy a higher octane fuel to get rid of pinging. It's the heavy, constant knock that means you have a problem. Adding Equipmentto the Outside of Your Vehicle Things you might add tothe outside of your vehicle can affect the airflow around it. This may cause wind noise and affect windshield washer performance. Check with your dealer before adding equipment to the outside of your vehicle. 6-3