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Old 01-17-2013, 11:10 AM
awdrev awdrev is offline
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Location: Maryland
Join Date: Dec 2012
Posts: 82
Mein Auto: 2004 BMW X3 3.0 Auto Tran
Originally Posted by Supercourse View Post
Yes, I think that's the point.

DEX VI may claim to be downward compatible with the original fluid in a 2004 - 06 model, but unless you are having a complete power flush done, probably best to use something known to be closer to the original fluid.

In may be perfectly fine to do a drain and fill with DEX VI, but thinking about 2 fluids mixing together, it just seems better if they are as similar as possible in properties, additives, weight and even color (but that may be immaterial).
And I think that's a very valid concern Super and Brian.

I have decided to pursue the DEX-VI option and then do a second fill within 2000 miles to get the old fluid out. I chose DEX-VI for several reasons:

1) First and foremost it is what GM and BMW recommends. I think there's a conflict of interest between GM/BMW and other fluid manufacturers. BMW/GM are in the business of actually making and selling vehicles/transmissions which gives them a better edge when it comes to "what" to recommend to the user. While other brands (Castrol, Valvoline, etc) may work similarly, their goal is to grab as much of the market is possible thus their interest is to be as universal as possible.

2) GM's sheet indicates that DEX-VI is the exclusive upgrade to previous GM fluids. GM states that it is UPWARDS but not backwards compatible, I need not worry about that since I am not "downgrading" per se.

3) DEX-VI is the GM choice for new transmissions, and it's more universally available.

4) A critical point to me is that, according to GM, DEX-VI has a strong and long lifetime period. I am concerned that switching to a more universal fluid will force me to change the fluid in greater intervals than needed.

5) Finally, my substantial (and infinitely long) research gives me the impression that MOST owners are okay regardless of their choice of ATF. I have read great success with Redline, Castrol, LM, Mobile1, etc... Those that have used DEX-VI have also found their transmission to be working just fine after the change.

Thus, after beating a dead horse a million times, I think I have made my final choice. I will upgrade everyone once I am done with the procedure and hopefully I'll take some nice pictures.

I cannot thank you all enough for the vivid discussion, everyone has provided great detail and input that I hope others will also used when making their decision.

Last edited by awdrev; 01-17-2013 at 11:15 AM.
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