1996 Chevrolet S10 Pickup Owner's Manual - Page 229

Fu 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) for better vehicle performance and engine protection. Gasolines meeting the AAMA specification could provide improved driveability and emission control system 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 badenough, it can damage your engine. If your vehicle is certified to meet California Emission Standards (indicated on the underhood tune-up label), it is designed to operate on fuels that meet California specifications. If such fuels are not available in states 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 instrument panel may turnon and/or your vehicle may fail a smog-check test. If this occurs, return to your authorized GM dealer for diagnosis to 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 becovered by your warranty. In Canada, some gasolines contain an octane-enhancing additive called MMT. If you use such fuels, your emission control system performance may deteriorate and the malfunction indicator lamp on your instrument panel may turn on.If this happens, return to your authorized GM dealer for service. If you're using fuel rated at 87 octane or higher and you still hear heavyknocking, 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'thave to buy a higher octane fuel to get rid of pinging. It'sthe heavy, constant knock that means you have a problem. 6-3