FORD 2002 Mustang v.1 - Manual (Page 210)

It is recommended you use the appropriate
Motorcraft oil filter (or another brand meeting Ford
specifications) for your engine application.
BATTERY
Your vehicle is
equipped with a
Motorcraft
maintenance-free
battery which normally
does not require
additional water during
its life of service.
However, for severe usage or in high temperature
climates, check the battery electrolyte level. Refer to
the scheduled maintenance guide for the service
interval schedules.
Keep the electrolyte level in each cell up to the
“level indicator”. Do not overfill the battery
cells.
If the electrolyte level in the battery is low, you can
add plain tap water to the battery, as long as you do
not use hard water (water with a high mineral or
alkali content). If possible, however, try to only fill
the battery cells with distilled water. If the battery
needs water often, have the charging system
checked.
If your battery has a cover/shield, make sure it
is reinstalled after the battery has been
cleaned or replaced.
For longer, trouble-free operation, keep the top of
the battery clean and dry. Also, make certain the
battery cables are always tightly fastened to the
battery terminals.
Maintenance and Specifications
210