FORD 2013 Mustang v.3 - Manual (Page 157)

octane levels below 87 are not recommended. Premium fuel will provide
improved performance and is recommended for severe duty usage, such
as trailer tow.
• For Shelby GT500 octane requirements, see the Shelby GT500
Supplement.
• For Boss® 302 octane requirements. see the Boss® 302 Supplement.
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, see your 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 take a few seconds longer
than normal. With keyless ignition, just start the engine. Crank time
will be longer than usual.
• Normally, adding 1 gallon (3.8L) of fuel is enough to restart the
engine. If the vehicle is out of fuel and on a steep grade, more than
1 gallon (3.8L) may be required.
• The service engine soon indicator may come on. For more information
on the service engine soon indicator, see to Warning Lamps and
Indicators in the Instrument Cluster chapter.
Refilling with a Portable Fuel Container
WARNING: Do not insert the nozzle of portable fuel containers
or aftermarket funnels into the capless fuel system. This could
damage the fuel system and its seal, and may cause fuel to run onto the
ground instead of filling the tank, which could result in serious personal
injury.
WARNING: Do not try to pry open or push open the capless fuel
system with foreign objects. This could damage the fuel system
and its seal and cause injury to you or others.
156 Fuel and Refueling
2013 05+ Mustang (197)
Owners Guide gf, 3rd Printing
USA (fus)