Had the recall done at about 14k. Definitely seeing some better mpg and the DEF gauge seems to show less consumption. I was using about one box of DEF every 2k or so. See if it gets better. I just ran down to middle georgia and back from north carolina. Mostly flat, but i had the cruise on 75-80mph pretty much the whole way. Averaged 27.3mpg over 850 miles. Usually on a greenville trip, i was getting 24-25mpg avg. So about 2+mpg better.
Stock tires and a bed cover.