FORD 2013 Focus v.1 - Manual (Page 171)

FUEL QUALITY
Note: Use of any fuel other than those recommended may cause
powertrain damage, a loss of vehicle performance, and repairs may not
be covered under warranty.
Choosing the Right Fuel
Use only UNLEADED fuel or UNLEADED fuel blended with a maximum
of 15% ethanol. Do not use fuel ethanol (E85), diesel fuel, fuel-methanol,
leaded fuel or any other fuel because it could damage or impair the
emission control system. The use of leaded fuel is prohibited by law.
Choosing the Right Fuel With a Flex Fuel Vehicle (If Equipped)
Note: If your vehicle is flex fuel capable, it will have a yellow bezel
placed over the fuel fill inlet.
Flex fuel vehicles are designed to use only FUEL ETHANOL (Ed75-Ed85)
fuel blends which contains 51 to 83% ethanol and UNLEADED FUEL
“Regular” unleaded gasoline or any mixture of the two fuels.
It is best not to alternate repeatedly between gasoline and E85. If you do
switch fuels, it is recommended that you add as much fuel as
possible—at least half a tank. Do not add less than five gallons (18.9L)
when refueling. You should drive the vehicle immediately after refueling
for at least 5 miles (8 km) to allow the vehicle to adapt to the change in
ethanol concentration. If you exclusively use E85 fuel, it is recommended
to fill the fuel tank with regular unleaded gasoline at each scheduled oil
change.
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.
87
(R+M)/2 METHOD
Fuel and Refueling 171
2013 Focus (foc)
Owners Guide gf, 1st Printing
USA (fus)