Originally Posted by Ramfd
I have the same thing in my 2011 Durango with the V6. and was wodnering the same thing. I cant really find any more info about cylinder deactivation other than the quote on the pentastar site. I do know though on my 2009 ram with the Hemi, when it cuts to 4 cylinders it says fuel saver. I figured the ECO light was just a way to let you know that you were driving efficiently and saving fuel. Kind of a way to get you to drive more GREEN. not really a system activation or anything.
When I purchased my 09 Ram, the 'fuel saver' light was directly linked to the 'fuel saver technology', aka MDS system.
Fuel saver light would come on and go out in 100% synch with MDS.
Later, immediately after a flash at the dealer, the fuel saver light was no longer in synch with the MDS system. It came on whenever your were 'driving in an efficient manner' and was no longer dependent upon MDS activation.
The 'fuel saver' light on earlier models is the predecessor to the ECO light on newer vehicles.