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:
Replacing rear brake/tail/turn and sidemarker lamp bulbs
The brake/tail/turn/side marker lamp and backup bulbs are located in the
tail lamp assembly. Follow the same steps to replace the bulbs.
Note: Your vehicle is equipped with a tail lamp assembly c ...
Checking engine coolant
The concentration and level of engine coolant should be checked at the
intervals listed in scheduled maintenance information. The coolant
concentration should be maintained at 50/50 coolant and di ...
Under the Hood
Lincoln’s 5.4-liter V-8 engine develops 300 horsepower and 355 pounds-feet of
torque, and it mates with a four-speed-automatic transmission. The Navigator is
rated as an Ultra Low Emissions Vehicl ...
