Moving from TX to WI
 

So. I'm getting out of the Air Force and moving back to WI from TX. Its about a 1100 miles drive, and I'm going to be getting a uhaul trailer to get all my stuff back with me. I'm looking at getting a 5x8 trailer, which will have about 1500 lbs in it, if not less. This will be my first time towing anything more than a few hours, and only my second time towing anything in this truck. The other thing I towed was a 22 person pontoon boat that weighed like 7000 lbs. That DESTROYED my mpg :( well, i could probably blame the hills I was towing it up too. Damn you TX. My truck is a '05 duramax lly CC bone stock.

So, I've got a few questions:

1. I made the trip last summer, and got around 16 mpg. I spent around 250 -300 bucks in fuel one way. How much should I expect that to drop off? I'm figuring at least 400 bucks in fuel costs this time, does that sound right?

2. Anything I should lookout for/ not do while on the road?

3. Any tips/ tricks?

Thanks in advance.