Octane recommendations
Your vehicle is designed to use
“Regular” unleaded gasoline with
pump (R+M)/2 octane rating of 87.
We do not recommend the use of
gasolines labeled as “Regular” that
are sold with octane ratings of 86 or lower in high altitude areas.
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.
Fuel quality
If you are experiencing starting, rough idle or hesitation driveability
problems, try a different brand of unleaded gasoline. “Premium”
unleaded gasoline is not recommended for vehicles designed to use
“Regular” unleaded gasoline because it may cause these problems to
become more pronounced. If the problems persist, see your authorized
dealer.
Do not add aftermarket fuel additive products to your fuel tank. It
should not be necessary to add any aftermarket products to your fuel
tank if you continue to use high quality fuel of the recommended octane
rating. These products have not been approved for your engine and
could cause damage to the fuel system. Repairs to correct the effects of
using an aftermarket product in your fuel may not be covered by your
warranty.
Many of the world’s automakers approved the World-wide Fuel Charter
that recommends gasoline specifications to provide improved
performance and emission control system protection for your vehicle.
Gasolines that meet the World-wide Fuel Charter should be used when
available. Ask your fuel supplier about gasolines that meet the
World-wide Fuel Charter.
Cleaner air
Ford endorses the use of reformulated “cleaner-burning” gasolines to
improve air quality, per the fuel recommendations in theChoosing the
right fuelsection.
Running out of fuel
Avoid running out of fuel because this situation may have an adverse
affect on powertrain components.
87(R+M)/2 METHOD
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
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Maintenance and Specifications
334
•Use the same filling rate setting (low-medium-high) each time the
tank is filled.
•Allow no more than 2 automatic click-offs when filling.
•Always use fuel with the recommended octane rating.
•Use a known quality gasoline, preferably a national brand.
•Use the same side of the same pump and have the vehicle facing the
same direction each time you fill up.
•Have the vehicle loading and distribution the same every time.
Your results will be most accurate if your filling method is consistent.
Calculating fuel economy
1. Fill the fuel tank completely and record the initial odometer reading
(in miles or kilometers).
2. Each time you fill the tank, record the amount of fuel added (in
gallons or liters).
3. After at least three to five tank fill-ups, fill the fuel tank and record
the current odometer reading.
4. Subtract your initial odometer reading from the current odometer
reading.
5. Follow one of the simple calculations in order to determine fuel
economy:
Calculation 1:Divide total miles traveled by total gallons used.
Calculation 2:Multiply liters used by 100, then divide by total
kilometers traveled.
Keep a record for at least one month and record the type of driving (city
or highway). This will provide an accurate estimate of the vehicle’s fuel
economy under current driving conditions. Additionally, keeping records
during summer and winter will show how temperature impacts fuel
economy. In general, lower temperatures give lower fuel economy.
Driving style — good driving and fuel economy habits
Give consideration to the lists that follow and you may be able to change
a number of variables and improve your fuel economy.
Habits
•Smooth, moderate operation can yield up to 10% savings in fuel.
•Steady speeds without stopping will usually give the best fuel
economy.
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Maintenance and Specifications
336
ENGINE DATA
Engine 5.4L V8 engine 6.8L V10 engine
Cubic inches 330 415
Required fuel 87 octane 87 octane
Firing order 1-3-7-2-6-5-4-8 1-6-5-10-2-7-3-8-4-9
Spark plug gap1.02–1.28mm
(0.040–0.050 inch)*1.02–1.28mm
(0.040–0.050 inch)*
Ignition system Coil on plug Coil on plug
Compression ratio 9.8:1 9.2:1
*The 5.4L 3V and 6.8L 3V spark plug gap CANNOT be adjusted.
Drivebelt routing
5.4L V8/6.8L V10 engines
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Maintenance and Specifications
356
recommendations ...................321
refill capacities ........................352
Exhaust fumes ..........................234
F
Fail safe cooling ........................328
Family entertainment system ....43
Fluid capacities .........................352
Foglamps .....................................80
Four-Wheel Drive vehicles .......248
description ..............................252
driving off road .......................254
electronic shift ................248, 252
indicator light .........................249
lever operated shift ................250
manual locking hubs ..............248
preparing to drive your
vehicle .....................................239
Fuel ............................................330
calculating fuel
economy ..........................124, 335
cap ...........................................332
capacity ...................................352
choosing the right fuel ...........333
comparisons with EPA fuel
economy estimates .................338
detergent in fuel .....................334
filling your vehicle
with fuel ..................330, 332, 335
filter, specifications ........330, 350
fuel pump shut-off switch .....267
improving fuel economy ........335
octane rating ...................334, 356
quality ......................................334
running out of fuel .................334
safety information relating to
automotive fuels .....................330
Fuel pump shut-off switch .......267
Fuses ..................................268–269G
Gas cap (see Fuel cap) ............332
Gas mileage
(see Fuel economy) .................335
Gauges .........................................18
transmission fluid
temperature gauge ...................22
H
Hazard flashers .........................267
Head restraints .........................151
Headlamps ...................................80
aiming ..................................82, 84
autolamp system .......................80
daytime running lights .............81
flash to pass ..............................81
high beam .................................81
replacing bulbs .............86, 88–90
turning on and off ....................80
Heating
heating and air conditioning
system ...........................71–72, 75
Homelink wireless control
system ........................................112
Hood ..........................................315
I
Ignition ...............................231, 356
Infant seats
(see Safety seats) .....................184
Inspection/maintenance (I/M)
testing ........................................340
Instrument panel
cleaning ...................................309
cluster ........................................12
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Index
363
lighting up panel and
interior .......................................82
J
Jump-starting your vehicle ......290
K
Keyless entry system ...............146
autolock ...................................136
programming entry code .......146
Keys ...........................................149
positions of the ignition .........231
L
Lamps
autolamp system .......................80
daytime running light ...............81
fog lamps ...................................80
headlamps .................................80
headlamps, flash to pass ..........81
instrument panel, dimming .....82
interior lamps ...........................85
replacing bulbs ....... 85–86, 88–93
Lane change indicator
(see Turn signal) ........................85
Lights, warning and indicator ....12
anti-lock brakes (ABS) ..........235
Load limits .................................212
Loading instructions .................218
Locks
autolock ...................................136
childproof ................................140
Lug nuts ....................................289
Lumbar support, seats .............155
M
Manual transmission .................244fluid capacities ........................352
reverse .....................................245
Message center .................116, 122
english/metric button .............126
system check button ..............125
warning messages ...........119, 128
Mirrors ...................................96, 99
fold away .................100, 102–103
heated ......................................100
side view mirrors (power) .....100
signal .......................................103
Moon roof ..................................110
Motorcraft parts ................330, 350
N
Navigation system .......................43
O
Octane rating ............................334
Oil (see Engine oil) ..................319
Overdrive .....................................95
P
Parking brake ............................236
Parts (see Motorcraft parts) ....350
Pedals (see Power adjustable
foot pedals) ...............................104
Power adjustable foot pedals ...104
Power distribution box
(see Fuses) ...............................273
Power door locks ......................136
Power mirrors ...........................100
Power point .................................96
Power steering ..........................238
2008 F-250/350/450/550(f23)
Owners Guide (post-2002-fmt)
USA(fus)
Index
364