I've searched, and don't see any discussion of this topic on the board. The owner's manual calls for a Mopar product #4874464, which is expensive, and when I went to a Dodge dealer to procure, the tech tried to sell me a different product which he said was "equivalent". There was a great discussion about transmission fluid for the pre-2000 XJ transmission AX-15, which seemed to come to rest on substituting either Redline MTL (or MT90) or AMSOIL Synthetic for the Mopar-recommended substitute. What thinks you all about the NV3550? I'm inclined toward Redline MT90 unless someone wants to persuade me otherwise (my 2001 XJ has 306,000!).