I will be towing about 9,500 pounds ~600 miles from central North Carolina to Pensacola, Florida. I may try to avoid Atlanta traffic so I will using I-85 or a more southern route through Ga./Al.
My question is, should I de-select overdrive on my transmission (and what are the pros/cons for doing so).
I have a 250,000 mile, 2000 V10 Excursion with towing package and electric brake controller (trailer has a Hydrastar EOH braking system).
Thanks,
Tom

Depends on the load, grade and speed imo. I don't put my Tahoe in trailer mode ever when towing my boat -6500ish lbs. Never needed to. I would watch tranny temp and feel how engine is running. If it's lugging or tranny temp is hot than turn off od.

As far as traffic is concerned, I use the App "Waze".... its a freebe that will alert you to traffic snarls and reroute as well as radar trap/sitting police up ahead - not just here in North America but i have used it around the EU as well.

If you have a trans temp gauge, it can dictate what you can get away with... The trailer mode give a higher shift point (possibly harder shirft and may not give top gear as in a "sport mode" car) if your truck is popping and dropping through gears in the hills - cheaper to pay for the gas than a trans. once you are in an area where you can get up to speed and the truck is not laboring, I opt for the mileage and go back to trailer when coming up to a hill.

9500 is a good pull...how old is the trans fluid?

Its not common on Ford 4r100/E40d like your excursion has to need to put in 3rd from 4th unless it going in and out of lockup as trans is quite beefy unlike some 1/2 ton stuff, Smitty