For whats its worth my 2014 5.7 Laramie was ordered with the tow package and stays around 175 when not towing. I cannot remember what it was towing but not much change I don,t think. Hope that helps.
I will bet all the Laramie models if equipt with the tow package on the window sticker was given all the needed accessories that should be included with Tow Package. The Bighorn/Express models were and are Hit & Miss which is ********!
I have read in the Tow Thread an owner received a so called HD 8HP70 as well as a HD Trans cooler on his Window Sticker! I didn't think to look to see if that was on a 2500/3500 diesel or Not.
IMO: Everything that is needed for towing should be included in the package at 1 extra price. I can understand a HD Transmission/Larger Brakes/HD Hitch/ ect would be an added price to the sticker & ordered with what is needed by the owner.
But at least give the standard package the added wire harness/Trans Cooler/Brake Controller/ Class IV Hitch.-->These 4 things are the most important and should be included in the basic tow package. {Mine Does Not}. But also my window sticker says nothing about a Tow Package.
It only shows-->Trailer Tow with 4 pin/7 pin harness-Class IV Hitch-3:92 axle- No Trans cooler or Brake controller. I should have payed more attention at the time of purchase. I will just have to add them myself.