2003 FORD F SERIES MOTORHOME AND COMMERCIAL CHASSIS fuel type

Fuel filter replacement
The fuel filter assembly is located inside the driver side frame rail, near
the transmission.
The fuel filter should be replaced every 24 000 km (15 000 miles).
Removal
If the fuel filter is being serviced with the rear of the vehicle
higher than the front, or if the fuel tank is pressurized, fuel
leakage or siphoning from the tank fuel tubes could occur. To prevent
this condition, maintain the vehicle front end at or above the level of
the rear of the vehicle.
Do not smoke or carry lighted tobacco or open flame of any type
when working on or near any fuel related component. Highly
flammable mixtures are always present and may be ignited, resulting in
possible personal injury.
Fuel in the fuel system remains under high pressure even when
the engine is not running. Before servicing or disconnecting any
of the fuel lines or fuel system components, the fuel system pressure
must be relieved in order to prevent accidental spraying of fuel,
causing personal injury or a fire hazard.
1. Shut the engine off and relieve the fuel system pressure.
•Remove the Schrader valve cap
(located at the right rear of
intake manifold) and install the
EFI/CFI Fuel Pressure Gauge.
The EFI/CFI Fuel Pressure Gauge
310–012 (T80L-9974–B) is
available at a certified Ford parts
dealer.
Maintenance and specifications
71

amount of fuel in a full tank and a tank when the fuel gauge indicates
empty. Empty reserve is the small amount of fuel remaining in the fuel
tank after the fuel gauge indicates empty.
The amount of usable fuel in the empty reserve varies and should
not be relied upon to increase driving range. When refueling your
vehicle after the fuel gauge indicates empty, you might not be
able to refuel the full amount of the advertised capacity of the
fuel tank due to the empty reserve still present in the tank.
For consistent results when filling the fuel tank:
•Turn the engine/ignition switch to the off position prior to refueling,
an error in the reading will result if the engine is left running.
•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 kilometers or miles).
2. Each time you fill the tank, record the amount of fuel added (in liters
or gallons).
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:Multiply liters used by 100, then divide by total
kilometers traveled.
Calculation 2:Divide total miles traveled by total gallons used.
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
Maintenance and specifications
74

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.
•Idling for long periods of time (greater than one minute) may waste
fuel.
•Anticipate stopping; slowing down may eliminate the need to stop.
•Sudden or hard accelerations may reduce fuel economy.
•Slow down gradually.
•Driving at reasonable speeds (traveling at 88 km/h [55 mph] uses 15%
less fuel than traveling at 105 km/h [65 mph]).
•Revving the engine before turning it off may reduce fuel economy.
•Using the air conditioner or defroster may reduce fuel economy.
•You may want to turn off the speed control in hilly terrain if
unnecessary shifting between third and fourth gear occurs.
Unnecessary shifting of this type could result in reduced fuel
economy.
•Warming up a vehicle on cold mornings is not required and may
reduce fuel economy.
•Resting your foot on the brake pedal while driving may reduce fuel
economy.
•Combine errands and minimize stop-and-go driving.
Maintenance
•Keep tires properly inflated and use only recommended size.
•Operating a vehicle with the wheels out of alignment will reduce fuel
economy.
•Use recommended engine oil. Refer toLubricant specificationsin
this chapter.
Maintenance and specifications
75

1Ensure the correct automatic transmission fluid is used. Transmission
fluid requirements are indicated on the dipstick or on the dipstick
handle. Check the container to verify the fluid being added is of the
correct type. Refer to your scheduled maintenance guide to determine
the correct service interval.
Some transmission fluids may be labeled as dual usage, such as
MERCONand MERCONV. These dual usage fluids are not to be used
in an automatic transmission that requires use of the MERCONtype
fluid. However, these dual usage fluids may be used in transmissions that
require the MERCONV type fluid.
MERCONand MERCONV type fluids are not interchangeable.
DO NOT mix MERCONand MERCONV. Use of a transmission
fluid that indicates dual usage (MERCONand MERCONV) in
an automatic transmission application requiring MERCONmay
cause transmission damage. Use of any fluid other than the
recommended fluid may cause transmission damage.
ENGINE DATA
Engine 6.8L V10 engine
Cubic inches 415
Required fuel 87 octane
Firing order 1-6-5-10-2-7-3-8-4-9
Spark plug gap 1.3-1.4 mm (0.052-0.056 inch)
Ignition system Coil on plug
Compression ratio 9.0:1
IDENTIFYING YOUR VEHICLE
Certification label for incomplete vehicles
On completed derivations of incomplete vehicles, the certification label is
affixed at a location determined by a subsequent stage manufacturer of
the completed vehicle. In these cases the completed vehicle is
manufactured in two or more stages by two or more separate
manufacturers.
Vehicle Identification Number
The vehicle identification number is attached to a metal tag and is
located on the front firewall to the right of the air filter.
If you ever find it necessary to communicate with Ford Motor Company
about your vehicle, always include the VIN in your communication.
Maintenance and specifications
92