I get 11 to 12 mpg city and can break 13 on a highway trip not towing or hauling anything. Pulling my trailer drops it down to 10 but I've only pulled maybe 4500lbs at the most. I did notice my mileage got better as it broke in. Have 6700 miles now and no problems or complaints at all. The mpg is just right where I expected it to be.

On a side note-that snow storm we got 2 wks ago had me keeping the SD in 4wd for several days stright due to I spent the first 2 days driving around in 20" of unplowed snow. Also did alot of idling. My mileage for that tank of gas was under 9mpg! Worth it though to be in the roughly 10% of vehicles that weren't rendered completely useless due to the deep snow. Even compact 4wd pickups and many smaller suvs/awd cars were going nowhere.