2001 Lincoln LS Owner's Manual - Page 228

Maintenance and care Repairs to correct the effects of using a fuel for which your vehicle was not designed may not be covered by your warranty. Octane recommendations Your vehicle is designed to use "Premium" unleaded gasoline with an (R+M)/2 octane rating of 91 or higher for optimum performance. (R+M)/2 METHOD The use of gasolines with lower octane ratings may degrade performance. We do not recommend the use of gasolines labeled as "Premium" in high altitude areas that are sold with octane ratings of less than 91. Do not be concerned if your engine sometimes knocks lightly. However, if it knocks heavily under most driving conditions while you are using fuel with the recommended octane rating, see your dealer or a qualified service technician to prevent any engine damage. 91 Fuel quality If you are experiencing starting, rough idle or hesitation driveability problems during a cold start, try a different brand of "Premium" unleaded gasoline. If the problems persist, see your dealer or a qualified service technician. It should not be necessary to add any aftermarket products to your fuel tank if you continue to use high quality fuel of the recommended octane rating. Aftermarket products could cause damage to the fuel system. Repairs to correct the effects of using an aftermarket product in your fuel may not be covered by your warranty. Many of the world's automakers issued the World-wide Fuel Charter that recommends gasoline specifications to provide improved performance and emission control system protection for your vehicle. Gasolines that meet the World-wide Fuel Charter should be used when available. Ask your fuel supplier about gasolines that meet the World-wide Fuel Charter. In Canada, look for fuels that display the Auto Makers' Choice logo. 228