F350 ZF 6 Speed Tranny Fluid

[Duffman77]

I am looking at changing out the oil in my manual tranny (07 F350 ZF 6 Spd). this tranny calls for an Mercon ATF. I am looking at 3 options right now.
Valvoline Syn about $5+/L (not Mercon rated)
Mobil 1 $8+/L
Amsoil $11+/L
Obviously I believe the order of quality is reflected in the price but I dont want to pay 2x what I have to. Does anybody know which are Gr III or IV? Any other comments.

Links Below:
http://www.valvoline.com/pages/products/product_detail.asp?product=63
http://www.mobil1.com/USA-English/MotorOil/Other_Products/Mobil_1_Synthetic_ATF.aspx
http://www.amsoil.com/StoreFront/atf.aspx

 

[unDummy]

Is RoyalPurple synchromax available? That would be my 1st choice.

Its a coin toss with the above fluids. But, if you're not happy with the shift feel, its money wasted regardless which fluid was used.

 

[SteveD2]

I know I had trouble with RP in my NV5600, but it works well in my transfercase which is spec'd for ATF+4...I would not hesistate to use it in a manual tranny that spec'd ATF.

steved