FYI, my 05 MR with turbo upgrade and cams, the last time I got over 300miles for the tank

 

I recently started to get around 17~18 mpg on pump gas on my IX so I put in a new front o2 sensor and instantly gained 40-60 miles per tank (city/highway)

 

same problem here.. I see maybe 190 miles with a full tank 93... Running big full 3 inch exhaust and a lil over 420 to the wheels. I short shift, try and stay out of boost and have only 1 spot on my way to and from work that I really get on it at all. I have 272s as well. The mileAge is killing me. But I've also found that being in to higher gear can be just as detrimental to your mileage as changing at 6k all day. Tend to shift at 3k or 3500 for normal city driving.

 

Well I read and read all of the links that you guys posted here. then went and tuned and read some more and tuned some more. (it really only took a couple hours of 2 days. not as bad as I thought).
After it all I am very happy. I now have 0 nock every. My car idles better warm or cold. My AFRs are pretty darn close to right at what I want them all the time. I am pushing 3 more pounds of boost. making more power whenever I want it. And with all this I am now at just of 21mpg running kinda hard on freeway and what not and 25 ish normal in town driving.
This is all with my bent intercooler that is leaking. Really need to get that fixed.

 

At this point I stated over from the stock tune then changed maps of Mivec, Timing, up the boost, then fix AFR.