2003 Ford Taurus Owner Guide 3rd Printing - Page 180
2003 Ford Taurus Manual
Page 180 highlights
Maintenance and Specifications Do not use fuel containing methanol. It can damage critical fuel system components. Your vehicle was not designed to use fuel or fuel additives with metallic compounds, including manganese-based compounds containing MMT. 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 Do not be concerned if your engine sometimes knocks lightly. However, if it knocks heavily under most driving conditions while you are (R+M)/2 METHOD using fuel with the recommended octane rating, see your dealer or a qualified service technician to prevent any engine damage. 87 Unleaded Gasoline engines Your vehicle is designed to use "Regular" unleaded gasoline with an (R+M)/2 octane rating of 87. We do not recommend the use of gasolines labeled as "Regular" that are sold with octane ratings of 86 or lower in high altitude areas. FFV engine (if equipped) Your vehicle is designed to use (E85) Fuel Ethanol, "Regular" unleaded gasoline or any percentage of the two fuels combined. U.S. government regulations require fuel ethanol dispensing pumps to have a small, square, orange and black label with the common abbreviation or the appropriate percentage for that region. Use of other fuels such as Fuel Methanol may cause powertrain damage, a loss of vehicle performance, and your warranty may be invalidated. 180