FUEL QUALITY
Choosing the Right Fuel
Your vehicle is designed to operate on
regular unleaded gasoline with a minimum
pump (R+M)/2 octane rating of 87.
Some fuel stations, particularly those in
high altitude areas, offer fuels posted as
regular unleaded gasoline with an octane
rating below 87. We do not recommend
these fuels.
For best overall vehicle and engine
performance, premium fuel with an octane
rating of 91 or higher is recommended. The
performance gained by using premium fuel
is most noticeable in hot weather as well
as other conditions, for example when
towing a trailer. See Towing (page 209).
Do not use any fuel other than those
recommended because they could lead to
engine damage that will not be covered by
the vehicle Warranty.
Note: Use of any fuel other than those
recommended can impair the emission
control system and cause a loss of vehicle
performance.
Do not use:
• Diesel fuel.
• Fuels containing kerosene or paraffin.
• Fuel containing more than 15% ethanol
or E85 fuel.
• Fuels containing methanol. •
Fuels containing metallic-based
additives, including manganese-based
compounds.
• Fuels containing the octane booster
additive, methylcyclopentadienyl
manganese tricarbonyl (MMT).
• Leaded fuel (using leaded fuel is
prohibited by law).
The use of fuels with metallic compounds
such as methylcyclopentadienyl
manganese tricarbonyl (commonly known
as MMT), which is a manganese-based
fuel additive, will impair engine
performance and affect the emission
control system.
Do not be concerned if the engine
sometimes knocks lightly. However, if the
engine knocks heavily while using fuel with
the recommended octane rating, contact
an authorized dealer to prevent any engine
damage.
FUEL FILLER FUNNEL
LOCATION
The fuel filler funnel is located in the spare
wheel storage tray.
RUNNING OUT OF FUEL
Running out of fuel can cause damage not
covered by the vehicle Warranty.
If your vehicle runs out of fuel:
• Add a minimum of
1.3 gal (5 L) of fuel
to restart the engine. If your vehicle is
out of fuel and on a steep slope, more
fuel may be required.
• You may need to switch 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. When restarting, cranking time
takes a few seconds longer than
normal.
156
Flex (), enUSA, First Printing Fuel and RefuelingE161513
ENGINE SPECIFICATIONS - 3.5L DURATEC
3.5L V6
Engine
214
Cubic inches
Minimum 87 octane
Required fuel
1-4-2-5-3-6
Firing order
Coil on plug
Ignition system
0.049 - 0.053 in (1.25 mm - 1.35 mm)
Spark plug gap
10.8:1
Compression ratio
Drivebelt Routing
3.5L Engine ENGINE SPECIFICATIONS - 3.5L ECOBOOST™
3.5L EcoBoost
Engine
214
Cubic inches
Minimum 87 octane
Required fuel
1-4-2-5-3-6
Firing order
Coil on plug
Ignition system
0.0295 - 0.0335 in (0.75 mm - 0.85 mm)
Spark plug gap
10.0:1
Compression ratio
299
Flex (), enUSA, First Printing Capacities and SpecificationsE191904
