Interesting how the tag is worded. WARNING means to me that if you change the fluid or top it off something bad is going to happen. I take the word necessary as I don't have to change the fluid but it doesn't indicate to me that something bad is going to happen if I do. May be a language thing.

It's easy to see why the debate never ends especially when this same tag is not on all transmissions. Not unusual to lump all E53 transmissions into one bucket adding to the confusion of the debate.

I always follow the fluid and oil debates for entertainment and to watch for a new contribution that puts an end to differences of opinions.

I decided to call an expert at IPT Performance Transmissions. They are a will know builder of ZF performance transmission as well a host of others. I have spoken with John before about a high stall speed performance transmission which is on my list of future mods.

(The following is a paraphrase of my conversation with John which means may have misunderstood something he said) In addition to the article link he said the ZF valve body is highly taxed and old fluid will contribute to wear similar to valve lapping compound. He also mentioned that German fluids are different. He uses Febi fluid as it is the same formulation as BMW fluid. He said fluid is much better than the old days so the change interval is longer but since old fluid suspends abrasive material a flush and new fluid is beneficial to the transmission life.


Article Source: Transmission Flush Myths - Busted!

Here is the sticker on the 5L40-E/GM5 (A5S 390R) on my 2001 3.0i.

It seems very clear to me, although I changed the ATF. BTW, googling for that part number, following only official sources, etc. I ended up that Dexron VI is now the BMW approved ATF for these transmissions. So yes, BMW changed their story since the cars were manufactured.

I also found official BMW sourced documents that say that the old oil is to be replaced if the pan needs to be dropped.

BTW, my reading of "lifetime" is to mean the lifetime of the component - the AT. Similar to suspension components that have grease in them but no zerk fitting to add more. The joint should wear out before the grease stops working.

BTW, excellent point about the GM vs. ZF transmissions - I consider them to be very different, which is why I always make it clear in my posts which one I have.

I don't expect the IPT input to resolve the debate. Some minds won't accept a change in belief and someone will probably find another expert that will disagree.

I feel very comfortable accepting IPT conclusions verses our interpretations of BMW tags, assumptions we make, our personal experience with one ZF transmission or even, if it were ever possible, a consensus of opinion on this forum.

For those of us that are not ZF transmission specialists, regardless of what we stout, it is prudent to bow to one with years of experience with transmissions, especially when their knowledge has resulted in high performance improvements to the ZF and a wide range of other transmissions.

Hey Guys
Newbie here to the X Family..I've had my 04 3.0 for 3 weeks and I'll be posting a few obeservations...

I've always used Mobil 1 ATF in all my Bimmers, Audis and Rovers..never an issue. Just did my 3.0 and swapped 3 quarts. I will do another flush in a couple of months.

The fluid on my 04 3.0 came out pitch black..The truck shifts a lot better with Mobil synth ATF.