My wife's new 2012 seems to work well. I can hardly tell the difference between on and off. Going down the road, when the ECO light is on, sometimes there is a slight almost vibration, not hardly noticible. Give it any pedal at all, and the power is right there. I'm assuming this has to be saving gas, and it doesn't affect drivability, so whats the problem? The only thing I don't understand is why it doesn't do it at idle, like at stoplights... that seems like a logical place to cut cylinders and save fuel!! Earl ....... PS We love our HEMI'S!!!