FORD 2015 Flex - Manual (Page 192)

• Leaded-fuel (The use of leaded fuel is prohibited by law).
Note: Use of any fuel other than recommended fuel can cause
powertrain damage, impair the emission control system or cause loss of
vehicle performance. Any damage to vehicle that is caused by use of fuel
not recommended will not be covered under warranty.
Octane Recommendations
3.5L V6 TiVCT Engines
We recommend regular unleaded gasoline with a pump (R+M)/2 octane
rating of 87. Some stations offer fuels posted as regular with an octane
rating below 87, particularly in high altitude areas. We do not
recommend fuels with octane levels below 87.
3.5L V6 EcoBoost Engines
We recommend regular unleaded gasoline with a pump (R+M)/2 octane
rating of 87. Some stations offer fuels posted as regular with an octane
rating below 87, particularly in high altitude areas. We do not
recommend fuels with octane levels below 87. To provide improved
performance, we recommend premium fuel for severe duty usage such as
trailer tow.
Do not be concerned if your engine sometimes knocks lightly. However, if
it knocks heavily while you are using fuel with the recommended octane
rating, contact an authorized dealer to prevent any engine damage.
RUNNING OUT OF FUEL
Avoid running out of fuel because this situation may have an adverse
effect on powertrain components.
If you have run out of fuel:
• You may need to cycle the ignition from off to on several times after
refueling to allow the fuel system to pump the fuel from the tank to
the engine. On restarting, crank time will be a few seconds longer
than normal. With keyless ignition, just start the engine. Crank time
will be longer than usual.
• Normally, adding 1 gallon (3.8 liters) of fuel is enough to restart the
engine. If the vehicle is out of fuel and on a steep grade, more than
1 gallon (3.8 liters) may be required.
• The service engine soon indicator may come on. For more information
on the service engine soon indicator, see Warning Lamps and
Indicators in the Instrument Cluster chapter.
Fuel and Refueling 191
2015 Flex (471)
Owners Guide gf, 1st Printing, October 2014
USA (fus)