Weird ZF6 Transmission Issue

[robnitro]

Originally Posted by dmbabu

Interesting. I have an F31 with the ZF8 transmission which can disengage (for coasting). Didn't know the ZF6 can also disengage for economy.

Yep. I was watching the fuel rate in bimmer-tool Android app when stopped in D and saw it go from 8mg/R (milligrams per revolution ) to 7.
Releasing the brake, it went back up to 8.
Another time I flipped over to S and shifted to 2 while stopped, same thing, fueling jumped up. (Can't do the disengaging in 2 as it uses a different clutch than 1)
For comparison, switching to N , the fueling goes down to 5 or so. The disengagement uses more fuel than N because the transmission is still active, it just cuts the torque going through the converter by disengaging clutch A IIRC.

I'm running my own xhp custom tune but I never could find the switch that turns on this ability so I never thought I would have it, but it seems it's part of the basic program.
The only odd thing is that sometimes it won't happen at all and I cannot find a pattern it's linked to, whether it be engine temp or transmission temp.