I have an 09 ram w/hemi and mds. I have never noticed anything that would indicate that the MDS is or is'nt working, how do you know?

 

Not sure about the 09 but on my 13, my ECO light comes on when MDS kicks in. Also, if MDS is on and I go around a corner, I can tell the lack of power. Hope this helps.

 

If you can't select the "display fuel saver" option on the trucks EVIC, then you either have the lower level dash or you need to have the dealer flash the truck for it.

 

Have to laugh. I just sold my '09. It was a very early '09. Like you no light or anything telling me the MDS was working. I just bought a '16 and you can definitly tell it is working. Sounds crappy when it is working. My '09 sounded awesome with the Mufflex muffler on it. I guess if you are getting 20mpg or so highway it is working?

 

On my '13 Sport, I have never seen the ECO light or felt any indication of MDS. I do get 20+ mpg at cruising speeds so ??? Don't know if MDS is active or not.