There's nothing wrong with the OPs car. Mine (2015 jetta) lost 6-8 MPG measured at every fill up after phase 1 and did not improve after phase 2.
It is also low on power, have to manually downshift to merge into interstate.\
Observations since phase 1.
Fuel quality seems to have went down, which would account for the occasional better tank mileage seen (3-4 low).
After phase 1, best mileage was at 70 mph or lower (low,low 40s)
After phase 2 best mileage is 78 mph or higher (mid 40's).
been to two different dealers both checked out car and said nothing wrong. However they have seen intakes clogging up with soot from EGR, causing problems.
Lastly DEF regens take 30-40 miles out of a tank full. Mine regens at least 3 times per tank. That is 90-120 miles of range lost, which accounts for the 6-8 mpg loss in MPG.
Before fix there was maybe one regen per 600+ miles.
It's NOT RUNNING RIGHT.
Sorry...you have nothing to compare it too...
I drove mine off the lot new in 2015...
Performance is the same, with perhaps slightly better MPG, certainly better DSG behavior, then new.
Regens still seem to be once per tank post fix #2
Mpg had always been 40-48 mpg seasonal...still is.
TQ band has changed a bit to encourage people to stay low in the RPM to get the MPG goals...but even heavy trucks have done this...high rpms in a diesel are counterproductive...makes noise, and makes you feel like you are actually accelerating faster...buts it's not....it's why typically "progressive shifting" is taught in DIESEL truck driving schools.use the TQ, not the rpms.
Yes...these cars are peppy off the line and initial accelerating, but not fast...
That why the reviews all said they were as exciting as "warm maple syrup"....