Engine Stop-Start (ESS) systems will be standard equipment on certain models of the 2015 Jeep Cherokee and 2015 Chrysler 200 mid-size sedan. The system will be used on four-cylinder 200s and V6 Cherokees; fuel economy should rise by around 3% with the new systems, which our sources claim are based on belt-driven generators.
The setup should become available in the Jeep Cherokee in the third quarter, and in the 200 in the fourth quarter. The setup is currently used in one version of the Ram 1500, where it saves one mile per gallon (city).
The ESS system uses a high-speed/high-durability starter that reduces crank time, for quicker restarts. Passive accelerator application is met with measured throttle response; hard inputs trigger aggressive starts. Chrysler claims, “there’s no waiting for either.”
When the engine comes to a stop, if it is warm enough for an immediate restart and there is sufficient reserve battery power, the engine is cut off, saving fuel. Heavier batteries maintain other vehicle systems, including the fan. When the brake is released, the engine automatically restarts (rather than waiting for the driver to use the accelerator), and the transmission re-engaged, within one third of a second. The feature can be deactivated by the driver at will.
As read on: http://www.allpar.com/news/index.php/2014/06/standard-stop-start-on-some-cherokees-200s