What will happen during ECO mode to the engine. Is some of the cylinders goes off without combustion ? If yes how many?
In pentastar 6 cylinders and in Himi 8 cylinders ?
For Grand cherokee 2011.
ECO mode changes your shift points to save fuel. The Hemi also has what is called MDS which shuts down 4 of the 8 cylinders in low load conditions. The shutdown cylinders still move mechanically with the engine they are just not burning fuel in them. The MDS can help your fuel economy out a good bit in highway cursing if you are in conditions where you stay in MDS a lot of your trip.
Finally, after 2 years, 2014 JGC can now retain the ECO Mode setting. So if you turn it off, the next time your turn your car on, ECO Mode will stay off. If you want this - check out TSB 21-004-15 !!!!