I have a 2021 z71 with that motor. It's quite and I average 26-27 mpg back and forth to work. I drive down a state hy set the cruse at 60 then a little stop and go in town. Only thing I have towed is a side by side. I only have 7k on it so far but I love the truck.
Love my 3.0, get 23mpg in town and on avg around 28-29mpg hwy with over 30mpg at times. Engine has more then enough power to pull anything within it’s ratings. I put 25k on mine in the year i’ve had it with around 12k of that towing, highly recommend it for it’s abilities yet efficiency.
I tow a 25ft camper, 14ft dump trailer and a 12ft utility trailer, even towed 12,000lbs when the gravel yard put more on my dump trailer then i wanted, do not recommend this but the engine handled it just fine going up steep hills.
It hardly uses def when not towing, start towing and it sucks the def down pretty fast.