I just bought an Airaid tube & connected it to my "stock" air box. Got me two mpg better mileage. Sounds nice when you rev it to 5,000 rpm as well. Auto Anything shipped overnight free.
My mileage has improved to 28.3 after installing an Airaid tube & K&N drop-in filter. I know after I tune it it may even get better but I am changing the oil 1st. I'll report back afterwards.
Mine's a 2012 3.7 and it's hold the button 6 seconds for full off. Also there is a button on the side of the Automatic shifter that will make the tranny a 5 speed instead of 6. push to turn on and off.