gas mileage

i wouldn't imagine that great. 12 - 15 maybe a little better but not that much.

I have a 5.9 in my 02 quadcab and get 16 highway so i would expect that you would get 1 or 2 less than that

I have the 5.9 2004 ... and i get 14 to 16 in the city and 20 to 23 on the highway! And thats unmodified as soon as i put an exhaust, intake and programmer on it ... i will get ALOT better miliage!

The 5.7 gets way better mileage than the 5.9. The 5.9 is a dog.

as soon as you put that stuff on it you'll be 100lbs heavier and no mileage better the 5.9 is p.o.s, you can expect 12-17 out of the 08 hemi, it will have mds so hiway will vary depending on what kind of terrain you are in.

The 5.9 Cummins is comparably 20 - 30% more efficient than the hemi. Even with the MDS on the hemi you'll be lucky to get 16 out of it. If your looking for the most MPG's, go with the diesel.

Agreed under these circumstances: 1. it is a 5.9L (older than 2004.5) diesel truck. 6.7L trucks don't see much better than 12 MPG because of the regeneration cycles of the DPF. 2. it is warm and gets to stretch its legs. If the oild burner is cold it will not get great milage at all. I see 16 US MPG on the road in the winter with lots of stop and go driving. If I get out and take for a burn the economy goes up to around 23. My truck is modded with a COMP, a SMARTY, 4" duals, FASS, 150 HP injectors, ATS manifold and a bunch of other such things.

a 2500 crew cab 4x4 long bed and a 5.7 hemi gas milage