I thought I was doing bad in my 5.9 with 10 mpg and 35's... And yeah, the superchips is good and all for the 5.9, but just like the hemi, the sct is the premium setup, much more power available, and a much better tuner in general. I have seen and experienced the differences between both and it is very noticeable. For mps I dont know if it would make so much of a difference though...

 

i get 13-14 highway, and 9-10 city