09 Impreza 2.5i Ignition Timing (video)
 

So i decided to start hypermiling with my beloved 09 impreza which i recently bought used with 31k miles on the odo. The thing was in a bit of dirty state, i think the previous owner took it offroading. Therefore i had the hood repainted, changed stone chipped fog light and headlight lenses and polished it up:

http://img684.imageshack.us/img684/6518/img1035su.jpg
http://img96.imageshack.us/img96/1779/img1039n.jpg

anyway. I was getting crappy mileage, worst than my RDX so i did a tune up over the past week. Replaced air filter, plugs, ran fuel injector cleaners and did seafoam. Replaced ATF and oil with lower friction synthetic fluids and drove it hard for a week to get everything broken in lol. This weekend i did a roadtrip of about highway with my Scangauge II plugged in. Average speed was 68mph and i heavily used the cruise control. Traffic was rather light and lane changing was kept at minimum. Cruising speed was with traffic,,, so from 60mph to 75mph. I was running 94 octane, 35psi tires cold ,ngk laser platinum plugs with -5'c weather and 60% humidity. I was very happy since i used to be getting 23mpg mileage before this tuneup, although i did have a lot of city driving. This is a 4 speed automatic 2.5L vehicle.

here is a small clip of my calibrated scangauge2, sorry about music:
20120219 195405 - YouTube

This time, with -10% adjustment:
Subaru Impreza Scangauge II - YouTube

Finally, My question is if my ignition timings seem healthy? at times i could see 38 IGN but only for short period of times, no matter what i did i could not keep 37-38 IGN. Why is that? Is this bad? anyway i can cruise at 38 ign or higher?