G0d Damn! I avg 30+ on the highway in my stg3 with many more mods. I avg 20-22 and sometimes more with a combination of highway/city driving. I drive pretty hard, have a bad o2 sensor, and just found out today that my timingbelt was off by a little. I would look into a reputable shop to get a new tune. Mine is custom from ASP. Call a few shops and see what they say. Car looks pretty good otherwise. Good luck with the sale!
I hate doing this and I'm sorry this ever turned into a debate, but did you even read what I had said? It was after a 120 mile roundtrip from NJ to NY with mostly highway driving. And No... idling does not get you a 30+ mpg. If you reset your OBC mpg calculator and just let it idle you'll see it slowly start to decrease from 14mpg or so. Was I supposed to take a picture of my mpg while driving, when I can do the exact same thing while stopped? Your logic to prove me wrong holds no weight. Although the OBC isn't a 100% accurate it gives a pretty close reading and by dividing the amount of miles I drive from full to empty by the amount of gallons I put in when i fill up I'm usually only 1-2 mpg off what the OBC says... which is like I said previously 20-22. I'm sure if you search around you'll see many other stg3 cars achieve this also. Have a good day. I'm done talking about this.