I tried the "tow mode" option today in my 20 minute (each way) commute to the jobsite for the house I am building currently. Wanted to see if the truck would "shift up" out of 10th and if the RPM's would change. Didn't see or notice a difference in or out tow mode.
My AT4X only has "normal", "terrain", or "offroad" for factory tune options. Terrain seemed to downshift me to a gear where the RPM's went up. Off Road mode really didn't work well, which it isn't meant for HWY driving I don't think.
I actually can't say I notice if AFM/cyclinder deactivation is happening on my truck. I am sure it is, but I don't notice it. I noticed it on my 2014 Z71 Sierra though. Just really haven't noticed it on the 23 AT4X.
I am going to do some google searching to see if I can find out what exactly "tow mode" is changing on this truck. I know usually that shift points and downshift points change in Tow Mode, at least traditionally. Also engine braking kicks in I believe. And I normally tow a large job trailer a lot. But haven't had to now for over 3 months. I always put the truck into Tow Mode when pulling a trailer, have dropped off the trailer and forgot to disengage Tow Mode back to Normal, and never was able to notice a difference.
The main thing I am looking to accomplish is to get rid of AFM so lifter issues become less likely. And other improvements - better MPG, better throttle response or power would be great, but doubt MPG would be better in Tow Mode vs Normal. Power, or at least seat of the pants power, could change given slower shift points.
I have driven trucks that have a "sport mode", and definitely noticed better throttle respons and power curve. Always figured the trade off would be worse MPG, which I am sure would be the case. Do wish my 23 AT4X had a "sport" mode. Ohh, well.