I agree that low gearing is pretty important in hauling.
I used to have 225HP F450 with manual and very low gear. When differential on it broke, I rented F550 with 320 HP automatic and almost created accident when that thing would barely move 18,000lb trailer on intersection. Than of following cold morning the RWD gearing would not pull the trailer from not that steep driveway.
I had to back up on flatter spot and gain some momentum.
Than with my F250 4WD I used the 4 wheel twice in 3 years. Once was when on steep driveway the empty pickup would spin wheels pulling 18k trailer, other time was hauling gravel on steep fresh fill.
But frankly I could avoid those 2 situations.
So my question still stands - how much mpg the truck loses with 4WD?
Even with disconnected hubs, you still have extra weight , extra height and extra transfer case gears to push.
Is it like comparing 17 to 16 mpg, or like 17 to 14?
When you calculate the 2 mpg difference over 50,000 miles before you use the option, it comes pretty hefty price.
Also how low is the low gear on new trucks?
FIY I am planning to move from CA to Las Vegas, where I doubt I will need 4WD for snow ;)
Thanks for the tip of more options while talking to commercial salesman.