On my test drives, the V6 got BETTER mpg than the 4 cyl.
Sounds counter-intuitive, but hear me out. The 4cyl topped out in 7th gear at 70 mph, and the engine was at about 2100 RPM. The V6 on the same stretch of highway dropped into 8th gear, and the RPM was about 1650 at 70 mph. I reset the lie-o-meter on both before starting the test drives, and when I drove back onto the lot, the V6 eeked out slightly better mpg on my 20 min drive of each. Small "sample" I know, but it was enough to convince me that the V6 was the way to go.
Even if the 6 only matches the 4 cyl for mpg, it's still 90 hp advantage for very little penalty mpg wise. There is the initial cost for the V6 option, but I think it's worth it. That 3.6L pentastar (on which the 3.2L is based) has been good.