[Primus]

I believe some of them will say they only getting between 12 to 16 mpg, which I find low for having MDS. That would only happen if they have poor throttle control. :funny:
I believe that the MDS HEMI's are untapped in the fuel economy department, especially after seeing Mythbusters do a segment on hypermiling behind a big rig in a Magnum R/T and getting over 30 mpg. :jawdrop:
With that in mind, if I ever get a HEMI powered car or truck within the next year or so, then I would mod the engine with the usual bolt-ons and such and I could probably see 20 mpg average with the way I drive.
But, that's just my opinion, you will have to hear from the real owners.

 

[Primus]

Mine's an 06 (MDS started in 06), quad cab 4x4 hemi.

I just got mine, so I haven't got the right 'feel' for the truck yet but:

I did take a road trip with it, over 300 miles, 90% highway...and it got 13mpg. That was with 4 guys and our crap. Right now the overhead computer says 9.9...Ouch!

I think you need to do the usual tune up and fluid change soon. Also, check the tires and exhaust, you are having any misfire(s) and sluggish throttle response.