2012 Toyota Tundra 5.7 SR5 Towing Package

I'll use drive and tow mode on back roads. It will stay in gear longer before upshifting, and it firms up the shifts. problem with drive however, is it will eventually look to go to 6th gear which is to high of a gear for any towing duty. On the interstate I'll manually select 5th. If I'm pulling a hill and it won't stay in 5th, i'll select 4th. I haven't found a interstate grade I couldn't pull in 4th. The torque converter locks up in 4th, 5th and 6th, however it won't lock in 4th if you have the shifter in 5th, 6th or drive.

The tow/haul switch on my 2010 does more than just change the shift points...Well thats what my tech at the shop tells me. I've seen what you describe, but I've always towed with it in tow mode. Towing my cargo trailer I get 1 mpg better in tow mode than not ... Never tired when towing my rv.

Oh, I had rather kept my Tundra but what is done is done.

I had a 2010 Trd, 2wd, 5.7 and loved it. My TT is 5700 dry - 7500 GVWR. I had no problem and had more gitty up & go than my 2500 does (tundra weighted less of corse). Did not have the problem you mentioned. The ONLY reason I switch was found the 2500 and cost basically nothing to trade & MOSTLY because of the payload difference 3200 vs. 1500 lbs.

I hope my info helped some.