anyone tow with a 6.8 v-10?

It will work great for what you plan. I'm a diesel mechanic by trade but I own/tow a 6.8 V10. I do a few trips a year, not worth the issues with most of the late model diesels. I have about 90K on my 2004, no issues at all. I get 6.5 towing my Rage'n which at the trucks max towing capacity. 12.5 is about the best you can do mixed driving empty. Like others posted mods aren't necessary. I put a large body Magnaflow on mine because I could not stand the OEM exhaust. (Sounded like a huge blow drier.)

I owned on of the original 2V, basic crank V10s, now I have the same one you are considering.

Mileage is what people above have stated 7-8 towing, maybe 13 hiway only, moderate speed.

I looked real serious at all the possible "upgrades":
* Tuners (esp 5-Star) can help, but looking at honest (not market hype) improvements implied that the pay-off would never happen.
* Any intake mod would allow more dust/dirt in the the engine, good for rebuilders, not good for your pocketbook.
* Any exhaust "upgrade" would be because you don't like the sound or just to spend money.

Ford really nailed it with this engine.

It will tow it fine. Forget the tuner and other add ons, not needed.

Had an economy tune in mine for a while, not worth it. I have a 4"lift and 285's underneath and get around 13.5 being light on the gas pedal. As for towing I pull the mountains of Colorado just fine, and of course she likes the higher rpms, so as the others said let her rev! Towing a 25' TH with either 2 four wheelers and 120 gallons of water and 30 gallons of extra fuel and loaded for fun. Weighed in prior to a hunting trip at 18k.

Towed a heavy Mobile Suites 5er with a 2008 F-350 V-10 4:30 gears. Was an awesome towing machine. Handled the trailer extremely well and as other have said let er rev. It is a small block and wants to rev on hills.

WHy the tuner?

Are you planning on driving all 250 miles uphill? Really the only couple of long grades out of town can be taken with the stock engine HP and they only take a couple more minutes while driving 45. Increasing the power enough to go 55 or 65 up the 5 mile long hill is only going to make you go 20 MPH faster on a 6 minute long hill. So driving up it at 65 will be like 5 minutes, 45 will take 5.5 minutes. So what is the huge deal?

When I drove my Ford Edge up the 6% grade I10 going from Indio east towards Phoenix, I was doing 110 in 5th gear at 5,500 RPM, on a 6% grade! That car really flies! Leave the fast driving for the quads, motorcycles and cars.

Fred.

My weekend warrior was an FSW3200+2 so it was actually 41' long. It towed great. I put on about 12,000 miles in the year I had it, until it broke (minor-accident-induced structural failure). Bone dry from the dealer it topped 11,000 so it was close to 13k stocked with some water, but otherwise empty. 18,000 fully loaded (which wasn't hard to to with 18' of cargo space!).

What axle ratio? The 4.10 V10 tows great. The 3.73 V10 not so good. I had both.

I towed my11.5k fiver with an '05. Towed it great, but...you already know about the mileage. Expect 7-8 towing. Maybe 12 or a little better empty. Don't be afraid to let her rev high. Should meet your needs.