i've kept track of every fill up since 1.6 miles when i took delivery...
just like kirk said above, if I did a tiny bit more hwy i'd be seeing 18 average. since i'm still within that 6 month period of it being new, my foot likes to go a little further than necessary more often than not (i actually don't see that changing anytime soon)
to answer your question, i'm gettin 16.8mpg since i've had it.
I've seen 24.9 on long roadtrips before my tune
I got 25.8 after my tune and mods
I've seen 12.2 city-only before muahaha