I run mine ('17 Hemi) with the ECO mode off (light on the button) because it could feel the MDS (cylinder deactivation) coming on at 35 - 40 mph. With it off it doesn't come on till about 45 - 50 mph where it's pretty much unnoticeable to me. You can't turn off the MDS unless you get a tune but buyer beware that it'll cancel your warranty.Just picked up a 2020 GC Summit 5.7 and have been reading up on the ECO mode.
From what I have found the engine cylinder deactivation can cause some issues long term that I am not interested in having to just save money at the pump.
I do however like the way the transmission shifts to the upper gears when I am just doing some city cruising. It's smoother with the ECO mode on.
Is there any way to have the ECO mode just do the transmission and perhaps the throttle tone down but NOT shut down have the engine?
If I ever need to feel the full power I can just flip it in Sport mode.... most of my driving is between 25-45 miles an hour in the city.
thanks in advance