Ford 1999 Mustang Owner's Manual page 216

Filling station information
1
Use Ford Premium Engine Coolant (green in
color). DO NOT USE Ford Extended Life Engine
Coolant (orange in color). Refer to Adding engine
coolant, in the Maintenance and Care chapter.
2
Service refill capacity is determined by filling the
transmission to the bottom of the filler hole with the
vehicle on a level surface.
3
Ensure the correct automatic transmission fluid is
used. Transmission fluid requirements are indicated
on the dipstick or on the dipstick handle. MERCON
and MERCON V are not interchangeable. DO NOT
mix MERCON and MERCON V. Refer to your
Scheduled Maintenance Guide to determine the
correct service interval.
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