[cowboyt]

I have as of yet to find anyone stocking the 236.10 fluid. Might it be better?? Maybe...... But.... Unobtanium....

Ebay-tanium, actually.

https://www.ebay.com/sch/i.html?_fr...TRS0&_nkw=transmission+fluid+236.10+&_sacat=0

Mercedes Benz 10 Liter MB Spec 236.10 Red Automatic Transmission Fluid Oil ATF | eBay

10-Liters Mercedes Automatic Transmission Fluid (MB Spec 236.10)

I'm currently using the Meyle 236.10 in my '03 S600 TT. As you'd expect, it works beautifully. I will also use it in my 2005 E320 CDI (722.6 transmission) soon as I get a chance to do that car's tranny service.

I use 236.12 in all of my transmissions. Don't know if it's any better, just my choice.

Nothing wrong with 236.12, either. I currently have Febi Titan 236.12 in my '03 S430. Judging from how well it shifts, the transmission likes this fluid quite a bit.

Same here, 236.10 fluid is not available.
I have used MB 236.14 in my cars and all are going well.

I've used 236.14 (specifically, Shell ATF 134) in the 5-speeds as well, and sure, it works great. The last one I did that on was a 2003 C230 Kompressor with the 722.6 transmission. Guy's scootin' around all over town.

 

[cowboyt]

I am about to do a complete transmission fluid flush and I have seen on other threads members talking about using 236.10 in old transmissions (mine has 220K Km) instead of the 236.14. Could someone confirm that this is better suited for old transmissions than the new upgraded ATF 236.14 despite the fact that MB claims 236.14 is backward compatible?

It's neither "better" nor "worse"; it's simply a matter of transmission feel. Since the 236.14 fluid does have a slightly lower viscosity, your shifts will feel a little more firm. This is said to actually be good for the transmission. The 236.10, being a bit higher in viscosity, will tend to have slightly smoother shifts. Many people prefer this (I'm one of them).

Any of the three--236.10, 236.12, or 236.14--and any mixtures of these three--are correct for the 5-speed 722.6 transmission (not so for the 7-speed 722.9 transmission--that's 236.14-only). All three fluid types are compatible with each other, so no worries there, either.