2006 Ram 1500 HEMI Quad Cab 2wd...MPG?

What could I expect MPG wise from one of these trucks? Interested in ditching my jeep as a daily driver and getting a pickup. I have an 11 mile commute that is almost all highway.

Also, on trucks with MDS(does 06 have it?) do these things go to sounding like a tractor when the MDS kicks in? I am sure you couldn't hear it with stock exhaust but with something louder is that a problem?

Thanks!

I have a 2007 Ram 1500 with the 5.7 HEMI and a 3.55 diff. I can get near 20 on the freeway if I stay on flat ground between 55 and 60 mph. Over 65 and it really drops the economy.
The 2006 1500 models were the first to get the MDS system. With a stock exhaust system, the exhaust tone is hardly different when the MDS engages. I have a Flowmaster muffler and twin tailpipes. I can hear a change, but it isnt bad. I would expect it to be more dramatic with a cheaper or louder type of muffler.