22 yukon XL Denali, 6.2 Gasser. Just did a 550 Mile Road trip, with some thrown in city miles and starts/stops, averaged 17.8 for the entire 553 miles. Ran 92 octane from Costco. Best 50 Mile Stretch was 22.6 according to the vehicle computer.
In town driving here in Frigid Minnesota is around 14-14.5 right now, not much warming up/remote start.
My 2013 LTZ Suburban with 5.3 and Max Trailering Package usually got 13-13.5 in town in same temps in winter, and about 17.5 on the same type road trip as this one.
Therefore, I am pretty satisfied w/ the 6.2, as it is +90HP, +900cc of displacement, and getting the same fuel economy. I am also expecting things to get a bit better with a few more miles (only 1300 on the clock so far), and warmer temps in spring/summer.