FORD 2002 Focus v.1 - Manual (Page 289)

Maintenance and Specifications
289
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
Use the same filling rate setting
(low - medium - high) each time
the tank is filled. Allow three
automatic clickĆoffs when filling.
Always use fuel with the
recommended octane rating of a
known quality gasoline, preferably a
national brand.
It may seem insignificant, but you
should use the same side of the
same pump and have the vehicle
facing the same direction each time
you fill up. The driver should also
have the vehicle loading and
distribution the same every time.
Your results will be most accurate if
your filling method is consistent.
This is also true when calculating
fuel economy.