Resurrecting a dead thread. I just bought a 2017 R and so far I am in love, its bone stock so its slower than my APR stage 1 MK7 GTI I traded in for the R. (Tune is coming). I posted about my drop in fuel mileage on my commute and someone said I need this Haldex tune for some better MPG but reading all 13 pages it doesn't appear this tune would do anything to help economy.
It seems to me that the rear diff already decouples when cruising how it comes stock, or at least that is my understanding? I thought that was the point of the Haldex.
Also my car has zero wheel-spin that I can tell, granted stock. It launches hard, and its in the high 30's low 40's F and moist and on performance all seasons. This is just an observation and a guess but I wondered reading the bulk of this thread, it seems some still have wheel-spin and some this tune helps or eliminates. I also was reading up about troubleshooting the Haldex and some of the common issues, and I was wondering perhaps the folks that aren't seeing an improvement have a fault in the Haldex or the filter screen is plugged or something.
For $600, at this time it doesn't seem worth much to me, I have yet to really push the R since its winter, or maybe I am too used to my GTI. Maybe my feelings will change once I get the EQT stage 1 tune.