Lol, yeah that's not happening with a 6.7 in any body style.
I've never had a DRW, just SRW so my numbers may be slightly higher.
2007 6.7, reverse level, 33" tires (305/55/20),fully deleted, 3.73 gearing, T4 366 turbo, draconian tuned TCM and draconian EFI-live tuning.
12-13mpg in town...