A month ago I posted about the http://www.rpod-owners.com/forum_posts.asp?TID=4438&title=electronic-gauge-for-tv-interceptor - multi-function gauge I purchased, mostly to keep track of true coolant temps, oil temps, and torque converter slip while towing.  

Last week I had a large secondary https://www.etrailer.com/Transmission-Coolers/Chevrolet/Suburban/2010/D13504.html?vehicleid=2010747853 - transmission cooler installed, in addition to the secondary cooler from the factory as part of the heavy-duty towing package.  Last summer I ran very warm due to the cargo tray and generator in front of the truck and this should take care of that problem.  From everything I've read you can't cool a tranny too much, with the exception of initial startup with temps well below freezing.  So far I've seen the temps stabilize 40-50 degrees cooler than it did before so it is a good start.

I also swapped out the all-terrain tires with low rolling resistance tires to help improve mpgs.  The all-terrains are great in the snow so I'll swap them back next December.  So far I've seen a 6% improvement but I've been a bit heavy on the throttle so I expect more.