I've been monkeying with the tune trying to see how much I can squeeze out of the car fairly bone stock (catless uppipe), before I do the downpipe and other money wasters.
I wanted to play with running higher AVCS degrees, but I noticed my left head would jump from 0* to 50*, while right head would be at 30* steady. I would say this is due to a clogged banjo filter and low oil pressure at 3k rpm, because at WOT both heads are in sync. Instead I played with target boost tables, wastegate duty cycle, and EGT scaling tables.
The target boost table and wastegate tables make the car be slightly less peppy at lower throttles, but that's fine on the highway I don't care about peppiness at low throttles. AVCS hole is filled with 10's, which is a known gain to MPG so I incorporated it in this tune. Finally the EGT part, I'm running a 2.2k-ohm resistor, which would make the ECU think the EGT's were 1292*F. I rescaled the EGT table to make it think it's 700*F at all ranges, which is around the degrees the stock catted up pipe setup was running at highway speeds.
With this setup, 26.9mpg
roundtrip, this is the highest I've gotten it since I did the uppipe/new o2! For a while I was stuck at 24-25mpg on 100% stock tune with up pipe and new O2 sensor. I want to play more with AVCS, but looks like I will need to pull the banjo filter first (and do the timing belt while I'm at it).
Edit: With further testing I'm not positive this configuration alone netted an MPG improvement, I think the terrain difference made the bigger difference. I've reverted to stock boost tables for better drive-ability.