2021 High Country, I am seeing 12.5-13.5 mpg
3" Cognito Leveling Kit, Stock 20s, 2" wheel spacers, on a Nitto 35x12.50 Ridge Grappler.
I am loving this truck, I have had a 2016 & 2016 Duramax, and I am super pumped about my switch back to gas.
https://photos.google.com/photo/AF1QipOExk9TI5ktgtgoW70Ld6iDvLk4WCu9_jNArWU5