I have a 2013 Ram with the 5.7, and even while traveling over 28 mph on flat terrain... and even with cruise on, the ECO notification never comes on. I also never notice a change in sound or driveability like some say they notice. I just bought it from a dealership last week. Is it possible the previous owner had a tuner and disabled it? I really don't care either way, as I've heard the MDS has a negligible effect on MPG.