Just got my '21 Bighorn 2 weeks ago (2nd year/3rd gen engine). Factory order took 10 weeks. Crew cab, 4x4, 3.21 gears, 33 gallon tank. Everything stock. Two short trips in the mountains. 55-65 mph average and total miles driven approx 150 each trip. Average mpg for both trips has been 31 mpg on gauge and hand calculated. Overall driving approx 800 miles: half time city and half time at 65/70 is averaging 26 mpg. Once we are out of city limits, we drive 80-85 on the interstate here, so obviously it's going to get ugly on those trips, but so far, super happy. Quietest, most comfortable truck I've owned. Dave.