2010 Mercury Mariner Owner Guide 2nd Printing - Page 309

Maintenance and Specifications It is best not to alternate repeatedly between gasoline and E85. If you do switch fuels, it is recommended that you add as much fuel as possible-at least half a tank. Do not add less than five gallons (18.9L) when refueling. You should drive the vehicle immediately after refueling for at least 5 miles (8 km) to allow the vehicle to adapt to the change in ethanol concentration. If you operate your vehicle 50% or more of the time on ethanol, you should follow a different maintenance schedule. In addition to this, if you exclusively use E85 fuel, it is also recommended to fill the fuel tank with regular unleaded gasoline once every 3,000 miles (4,800 km). See scheduled maintenance information for more information. Fuel quality If you are experiencing starting, rough idle or hesitation driveability problems, try a different brand of unleaded gasoline. If the problems persist, see your authorized dealer. Do not add aftermarket fuel additive products to your fuel tank. 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. These products have not been approved for your engine and 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 approved 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. Cleaner air Ford endorses the use of reformulated "cleaner-burning" gasolines to improve air quality, per the recommendations in the Choosing the right fuel section. 309 2010 Mariner (mrn) Owners Guide, 2nd Printing USA (fus)