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 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.
See also:
Refilling with a Portable Fuel Container
WARNING: Do not insert the nozzle of portable fuel containers
or aftermarket funnels into the Easy Fuel system. This could
damage the fuel system and its seal, and may cause fuel to run onto
the ...
The better business bureau (BBB) auto line program (U.S. Only)
Your satisfaction is important to Ford Motor Company and to your dealer.
If a warranty concern has not been resolved using the three-step
procedure outlined earlier in this chapter in the Getting ...
Vehicle storage
If you plan on storing your vehicle for an extended period of time
(30 days or more), refer to the following maintenance recommendations
to ensure your vehicle stays in good operating condition.
...
