Interesting question - I leave mine in 2hi - have a 2011 with the 5.3L V8 - what engine do you have and what mpg are you getting? I'm currently averaging 18.4 with around town mixed with short highway. 20.8 to 21.1 on hwy at average 72mph
I have the 5.3 4spd OD trailer towing package (axle ratio ?) and I get about 18 highway. The auto function is nice for mixed patch ice & boat ramps, but it looks like I'm going to switch to 2 hi now. We live in the city and avoid using the pickup since its hard on gas, clumsy in traffic & parking, and why wear out your truck when you can wear out the wifes cheaper car!
I always assume the t-case was running continuous and the auto lock was on the hubs after sensing wheel slip and 4 wheel function electrically locked the hub and what ever shaft was asked for.
