It sounds like you have the 3.73 diffy. I have a 2012 with the 4.30 diffy.
pends on what you are pulling, but i seldom use tow haul on the road since the thing is continually going nutso under the hood/ downshifting constantly.
yeah, yeah, I know it is spose to to that. ;)
I just prefer for me and that thing under the hood to have a little more relaxed atmosphere.
Some folks prefer to just let her rip tader chip.
Oh and prepare yourself for all the diesel folks to take the opportunity to bash a gasser.
If you are pulling any kind of weight at all and have the 3.73 diffy you probably will enjoy the ride more if you lock out 6th.