[Turkeybaster115]

Guys I did a lot of research as to what in the world the factory fill ATF (six speed automatic transmission ZF 6hp19/26) could be, and I think I finally found it. After a lot of searching, and phone calls to shell USA I have deduced the following:

According to the australian petrolium institute: http://www.lubeandtune.com.au/html/lubekey.asp their ASP15 classification includes the following fluids:
-Ford Specification No. M2C 919D
-Mercon SP Fluid Part No. XT-6QSP
-Shell ATF M-1375.4
-ZF 6-speed Automatic Transmission Fluid, (Shell M-1375.4)

Mercon SP Fluid is a newer transmission fluid made by shell for Ford dealers. Its easy to find online, and it retails for around $4:00+/quart. Things get really interesting when you look at the specs of lifeguard 6 found in the MSDS:
http://www.tsgparts.net/images/pdf/Lifeguardfluid6.pdf and compare them to the specs of Mercon SP:
http://www.fcsdchemicalsandlubricant...ERCON%20SP.pdf and http://www.fcsdchemicalsandlubricant...us175325us.pdf

VERY similar specs, and the same color fluid.

You can get the lifeguard6/Shell M-1375.4 fluid for $4.68/quart here: http://www.ryderfleetproducts.com/cg...uct_detail.jsp

Before you get this fluid consider the following; which are my opinions, drawn from online research. Shell was tapped by ZF/Ford, to make this fluid for maximum fuel efficiency. it has very similar specs to amsoil's fuel efficiency transmission fluid:

http://www.amsoil.com/storefront/atl.aspx (Scroll to the bottom of the page).

If you are in/out of warranty, want to change your ATF fluid, with oem, for considerably less than what the dealer will charge, then get the mecron SP stuff. Now for those who have higher torque vehicles with the 6hp19/26 transmissions, you might want to opt for a fluid that will trade you gas mileage for decreased fluid temps. This is especially true if you plan on occasional racing, or power increasing modifications. If you look at amsoil, and redline, you find that they each offer a line of racing/high temp fluid products. These products offer better thermal protection for racing or high torque vehicles. Looking closely, there're specs differ from the fuel efficient lines. Most notebly: KV @ 40C 7.5-10cst; KV @ 100C 34-53cst VI: 177+, Flash point 225 F+. Clearly the higher the fluid's KV/VI/Flash point, the more shear stable it is under abnormal stress.

The above listed racing fluids are on the high end. You can have slightly more thermal protection than stock with several other fluids(KV 40C: 7-8, KV 100C 34-38, VI 165+, Flash Point 212 C+:

-Castrol multi-vehicle atf TE ML 11A
-Pentosin ATF 1 TE ML 11B
-castrol transmax TE ML 11B, 14C!

None TE ML optoins include:
-amsoil universal atf
-valvoline max life
-royal purple ATF
-etc.