I have been researching the ATF4 for my dodge truck and from what I found the
Amsoil ATF has been used successfully in the dodge automatic transmission meeting their ATF4 spec. I just took a quick look at the specs at the bottom of the page for the 5W-40 Amsoil and the ATF and they have very different Kinematic Viscosities. Does this mean anything you tell me I really don't know? But from what I have read there are a lot of, or special friction modifiers in the ATF4 lubricants.
Both my cars had the original ATF changed in the first 5000 miles to mobil1 trans fluid with no friction modifier it was then changed out around 70000 miles for redline. There was a little easier shifts in the cold with the redline. I will probably change the fluid in one of the cars soon and I will report if I find anything unusual. But I really don't know what fluid to change to.
Something interesting to think about Honda Specs synthetic motor oil for their manual transmission.
