1997 Cadillac Eldorado Owner's Manual - Page 266

If your vehicle is certified to meet California Emission 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 Cadillac dealer before adding equipment to the outside of your vehicle. 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 turn on and/or your vehicle may fail a smog-check test. If this occurs, return to your authorized Cadillac 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 be covered by your warranty. Some gasolines that are not reformulated for low emissions contain an octane-enhancing additive called rnethylcyclopentadienyl manganese tricarbonyi (MMT); ask your service station operator whether or not his fuel contains MMT. General Motors does not recommend the use of such gasolines. If fuels containing MMT are used, spark plug life may be reduced and your emission controa system performance may be affected. The malfunction indicator lamp on your instrument panel may turn on. If this occurs, return to your authorized Cadililac dealer fox service. Use premium unleaded gasoline rated at 9 1 octane or higher. At a minimum, it should meet specifications ASTM D4814 in the United States and CGSB 3.5-WI93 in Canada. Improved gasoline specifications have been developed by the American Automobile Manufacturers Association (AAMA) for better vehicle performance and engine protection. Cholines meeting the AAMA specification could provide improved driveability and emission control system protection compared to other gasolines. Be sure the posted octane for premium is at least 9 I . If the octane is less than 91, you may get a heavy knockmg noise when you drive. (In an emergency, you may be able to use a lower octane -- as low as 87 -- if heavy knocking does not occur.) If you're using 91 or higher octane unleaded gasoline and you hear heavy knocking, your engine needs service.