FORD 1999 Windstar - Manual (Page 219)

The amount of 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.
Filling the tank
For consistent results:
• Use the same filling rate setting (low — medium — high) each time
the tank is filled.
• Allow three automatic click-offs when filling.
• Always use the recommended octane rating of 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.
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 kilometer (mileage) reading.
4. Follow one of the simple calculations in order to determine fuel
economy:
Multiply liters used by 100, then divide by total kilometers
traveled.
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
economy. Additionally, keeping records during summer and winter will
show how temperature impacts fuel economy. In general, lower
temperatures give lower fuel economy.
Maintenance and care
219