Anyone now where I can rent a 2500 series chevy truck for a week or so? I want to see how it is on gas mileage and I want to also see how it tows my boat. I looked at enterprise but they appear to only offer 1500 series in this area.

Any ideas?

I know that most rental companies don't allow you to tow anything. It's a problem if you get in accident, but then you are screwed

6.0 gas DONT even ask about towing milage. It shouldnt matter as long as you are going to the lake.
Non towing STILL sucks!
Get the Duramax.

enterprise around the chicago area rents ford f-350 duallies. you think they would everywhere

So let me clarify....

I drive 104 miles a day back and forth to work. The 2500 will be my daily driver so I want to calculate mileage on a tank or two.

In regards to towing, I know the whole deal with the rental agency not wanting me to tow. My plan was to tow the boat for 4-5 miles just to get a feel for how it handles.

These are actually pretty accurate:
http://www.fueleconomy.gov/feg/findacar.htm

Mileage per truck will vary on MANY things like:
tire size
wheel size
lift vs. lower vs. stock
bug deflector vs. not
big/small mirrors
windshield visor vs. not
4x4 vs. 2WD
cap vs. tonneau cover vs. open bed

a 6.0 2500 will be around 13-14 mpg average you might get a little better highway if you don't go 75-80 but not much and towing a boat like yours it'll probably be 8-10mpg. My boats weight is probably around the same as yours and my Avalanche has a 496 and I wouldn't want anything less