FORD 2013 F-550 v.3 - Manual (Page 196)

For consistent results when filling the fuel tank:
• Turn the ignition off before fueling; an inaccurate reading results if the
engine is left running.
• Use the same fill rate (low–medium–high) each time the tank is filled.
• Allow no more than two automatic click–offs when filling.
Results are most accurate when the filling method is consistent.
Calculating Fuel Economy
Do not measure fuel economy during the first 1000 miles (1600 kilometers)
of driving (this is your engine’s break-in period); a more accurate
measurement is obtained after 2000 miles–3000 miles (3200
kilometers–4800 kilometers). Also, fuel expense, frequency of fill-ups or
fuel gauge readings are not accurate ways to measure fuel economy.
1. Fill the fuel tank completely and record the initial odometer reading.
2. Each time you fill the tank, record the amount of fuel added.
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. Calculate fuel economy as follows:
Standard: Divide miles traveled by gallons used.
Metric: Multiply liters used by 100, then divide by kilometers traveled.
Keep a record for at least one month and record the type of driving
(city or highway). This provides an accurate estimate of the vehicle’s fuel
economy under current driving conditions. Additionally, keeping records
during summer and winter show how temperature impacts fuel economy.
In general, lower temperatures mean lower fuel economy.
EMISSION CONTROL SYSTEM
WARNING: Do not park, idle, or drive your vehicle in dry grass
or other dry ground cover. The emission system heats up the
engine compartment and exhaust system, which can start a fire.
WARNING: Exhaust leaks may result in entry of harmful and
potentially lethal fumes into the passenger compartment. If you
smell exhaust fumes inside your vehicle, have your dealer inspect your
vehicle immediately. Do not drive if you smell exhaust fumes.
Fuel and Refueling 195
2013 F-250/350/450/550 (f23)
Owners Guide gf, 3rd Printing, December 2012
USA (fus)