2013 Ford C-MAX Energi Owner Manual Printing 3 - Page 193

192 Fuel and Refueling Octane Recommendations Regular unleaded gasoline with a pump (R+M)/2 octane rating of 87 is recommended. Some stations offer fuels posted as Regular with an (R+M)/2 METHOD octane rating below 87, particularly in high altitude areas. Fuels with octane levels below 87 are not recommended. Regular unleaded gasoline with a pump (R+M)/2 octane rating of 87 is recommended. Some stations offer fuels posted as "Regular" with an octane rating below 87, particularly in high altitude areas. Fuels with octane levels below 87 are not recommended. 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 authorized dealer to prevent any engine damage. 87 Fuel Freshness Mode (Energi Vehicles Only) This feature helps keeps the fuel system functional and the fuel fresh. If you operate your vehicle mainly in plug-in power mode using electricity from plugging in without refueling, the gasoline in your tank eventually becomes old. Old fuel can damage the engine and fuel system. To prevent the fuel from becoming old, your vehicle will automatically enter fuel freshness mode. In fuel freshness mode operates, your vehicle will operate in hybrid mode causing the gasoline engine to run in order to consume the fuel in the fuel tank. Note: If new fuel is not added during an 18 month period, fuel freshness mode will consume fuel until about 1 gallon (3.8 liters) is left in the tank. During fuel freshness mode: • The information display screen will indicate that fuel freshness mode is active. • The vehicle will only run in hybrid mode. EV Now mode will not be available. • Most of the plug-in power will be stored until fuel freshness mode is completed. 2013 C-Max Full Hybrid (34h) Owners Guide gf, 3rd Printing, January 2013 USA (fus)