Mopar ATF-4/Is it a synthetic fluid?

[Dually]

I asked my service advisor at Jeep if Mopar ATF-4 was a synthetic fluid.He stated that it was not.I've heard that it was and it was made by Petro-Canada.I would love to use Amsoil ATF but according to Jeep the transmission fluid on the RFE545 needs to be changed every 30,000-40,000 miles with both filters.Info wouldbe great.Thanks Joe

 

[adam123]

my 05 Ram with the 545RFE says the fluid is a liftime fill. with normal service but I dont beleive it.

 

[TomJones76]

I believe that it's synthetic, assuming you will consider a quality Group III base oil to count as synthetic.
I cite a paper entitled "THE SYNTHETIC NATURE OF GROUP III BASE OILS" which lists both DaimlerChrysler ATF+4® and Ford Mercon® V ATF in a table titled "Synthetic Quality Products Utilizing All-Hydroprocessed Group III Base Stocks".
Whether or not Group III is synthetic or not is a TIRED argument on here, and I have no interest in rehashing it, however, if synthetic means "expensive", then by George, ATF+4 is synthetic.
About using Amsoil... I would trust Amsoil to make a good fluid, but for warranty purposes, I would ABSOLUTELY wait until this transmission was out of warranty. Reason being, if your transmission fails due to manufacturing defect, Chrysler may say "it's the oil's fault" and deny your claim. While you may have rights under Magnuson Moss in this situation, you will require a lawyer to EXCERCISE those rights. While Amsoil will warranty you against THEIR PRODUCT failing, if the transmission dies from manufacturing defect, Amsoil is under no obligation to get in the ring versus Chrysler on your behalf to prove that it was a manufacturing defect.

Cite:
[1] https://www.chevron.com/products/prodserv/BaseOils/docs/npra_paper.pdf
By the way, this paper is FASCINATING for dedicated oil geeks.