Not to add to the confusion or to hijack the thread, but I got a "pre-owned" Silverado (Contractor's edition). It has a button on the gear shift for "trailering" But I've yet to determine what it really does do. Does it just change the shift points or something else?
Edit: Maybe this is the answer from another thread?
mdamerell wrote:
Generally speaking there is a Tow Haul mode (button)which changes the shift points/pattern when engaged. It will hold a gear longer to help it pull better. Should minimize gear hunting. When slowing it will down shift the engine to give some braking assist.
Depending upon terrain and how much trailer you are pulling will determine how useful Tow Haul mode will be for you. Since it will reduce fuel economy some, some people only use it in the hills.
Put her in drive and see how your truck behaves with and without tow haul mode and use your best judgment.