OCI for my Chrysler 300M?

[Cory]

I currently have over 146K miles on my Chrysler 300M. Back @ 95K I performed a return line flush with Amsoil's Universal ATF. That's over 50K miles on the current OCI.

According to Maintenance Schedule "A" (Normal) I never need to change it. (Yes, I did a double take myself when I read this.) Schedule "B" (Severe) however states every 48K. Now I pretty much fall under the Schedule "A" scenario. I'm traveling a 100 mile round trip every work day (93% highway) along with the occasional short trips over to the in-laws and running errands on the weekend. (Equates to over 25.5K per year.)

Quote:
SERVICE LIFE
AMSOIL Synthetic Automatic Transmission Fluid is recommended for use up to 50,000 miles under severe service* and up to 100,000 miles under normal service* or according to the vehicle manufacturer recommended intervals, whichever is longer.


With the current 50K mile on this Amsoil Universal ATF, what are everyone's suggestions? Should I do a UOA now or should I be able to expect greater results of that compared to the Mopar ATF+4 that is suggested at a minimum of 48K? I also believe the Mopar ATF+4 is considered a synthetic? But like most 3K oil changes, is the suggested OCI under estimated? Thanks in advance to everyone's comments.

 

[Cooper]

I think most manufacturers recommend OCI for engine oil very conservative. ATF suggestions are more liberal, and usually a little longer than what should be run in the transmission.

Ever seen a manufacturer state "lifetime fill" for the transmission? Yeah, if you expect the lifetime to be less than 100k that is.

 

[The Critic]

Originally Posted By: Cooper
I think most manufacturers recommend OCI for engine oil very conservative. ATF suggestions are more liberal, and usually a little longer than what should be run in the transmission.

Ever seen a manufacturer state "lifetime fill" for the transmission? Yeah, if you expect the lifetime to be less than 100k that is.

OEMs routinely test their fluids out to 150k and beyond.

100k isn't unreasonable on the approved oil fill in this application.

 

[02zx9r]

with the highway miles you do I dont see why you couldnt go 50-75K easily *if* you wanted to.

 

[Donald]

You could do a UOA and check the condition of the ATF for wear metals. While I am sure the Amsoil ATF can go 50K or even 100K it builds up wear metals and not sure you want them them in the ATF for 100K miles.

So three options, 1) refresh the ATF at 15-20K with Amsoil ATF (this will pull some of the wear metals when you drain a few quarts), 2) do a UOA and see where you stand, 3) Install a filter like a Magnefine.

Would be great to do a UOA then install a filter then another UOA. Would give us all an idea on how well the filter is picking up wear metals.