Can you comment on what the performance improvement may have been. I Am interested but do have a 14 with 3.55 gears.
Sorry, just saw this comment. In terms of performance improvement, you'll see the throttle lag associated with the V08 recall go away. The engine felt more responsive, but only at levels that could be determined by a dyno (so minor HP and TQ improvement). DEF system can now run distilled water vs. DEF itself.
Where I saw gains was MPG. I daily drove my truck to work, a 50/50 commute city/hwy for about 10 miles. Without the tune, I averaged about 18 MPG. Post tune, I went up to between 20-21 MPG. Open highway, I saw high 20s to low 30s again traveling at 75MPH. I tow a small trailer (1500 lbs) for camping and I would normally see about 16-17.5 MPG on the highway prior to the tune. After the tune I was between 19-21 MPG depending on terrain.
Never had a reliability issue with the truck post-tune also (had on the truck for about 19k miles).