Brucer,

I did not know that FORD sold an additive for the ATX.
What is it called ??

Your ATX calls for only Ford MERCON fluid.
The only other fluid you should use in it would be Amsoil Synthetic ATX Fluid.

Get yourself at least 18 quarts to do a full oil change and add the fluid
to the transmission as the fluid runs out of the coolling line.
The fluid should run at the rate of 1 Liter/15 seconds @ engine idle.

Pete...

98.5 SE Sport Duratec ATX (P66L)
Black Clearcoat on Greystone
DOB 11/21/1997
DOP 12/25/1997
PIAA 510 Super White Driving Lights
SVT CAT-BACK EXHAUST (No Resonator)
DiabloSport Chip (LPQ4) - Engineered To Raise Hell
Too many other mods to list...
Sounds sweet, runs quick...
Crazy Horse Dyno @ 121.4 WHP/129.6 TQ