I tried out your AVCS table and changed upped my base timing a few degrees in the cruising areas. I managed 27mpg around 55-60, but that dropped to 24 at 70-75. how are you getting 31mpg?
05 OBXT manual, rebuilt 4k miles ago. full exhaust, 18g, sti manifold, 3mm spacers, tgv deletes, 06 wrx flywheel clutch combo, tuned with romraider.