I had a stock LMM 2500 EC/SB 4x4 that would get 17 empty hwy, 8 towing, & 14 city. MPG was a lot worse once the DPF was shot.
The stock LML 2500 EC/SB 4x4 that I "owned" got 16 empty hwy, 7 towing, & city driving 13.
When my LBZ was stock I got 19 empty hwy, havent towed yet, & 14 city.