Only on the 5.7 hemi

Manual says this:

The FUEL SAVER (ECO on later trucks) message will
appear whenever MDS (if equipped) allows the
engine to operate on four cylinders, or if you are driving

in a fuel efficient manner.

 

i do have the Hemi FTW!!!!

 

Mine does it all the time in "D" slowing down. I don't have to have it in tow/haul either. I can coast to a stop and watch the rpms jump up each time it downshifts on its own. Actually I really like this feature although I know some folks don't.

 

I wish mine did. I have an early build and i have to use the brakes pretty heavily. This truck can coast for days...