I just put my first tank of gas in my '13 i Touring hatch after purchasing it ~2 weeks ago. Surprisingly my avg MPG only came out to 29.2 MPG with conservative hwy driving and some city driving. I did some poking around and it seems people recommend resetting the ECU. I couldn't find a specific explanation on how to do this. It seems like the ECU is reset by disconnecting the battery for "x" amount of time, but then what? Am I jumping to conclusions that resetting the ECU could help more accurately recalibrate the system to equate to better fuel efficiency?