Mine doesn't kick in all the time...not sure if it's a glitch or if I'm not meeting the right criteria for it to kick in. It's a new feature to me so it's noticeable when it happens. It's not bad but you do feel a slight vibration when the engine stops and starts.
There are situations where it won't kick in. For example, if the outside temperature is too low, or the engine or cabin is not warm enough, it will not engage. I think it is also disable if hill assist is engaged, your wheels are turned, your hood or door is open, etc.
I wouldn't worry about undo wear on the engine, since apparently it only starts working when normal operating temperature is reached, so these are not cold starts. However, I just can't see how it can be good for the battery/starter/alternator. I like that we get these in more robust versions because of ESS, but I'm going to turn off ESS to make sure they last a long time too.
From what we've been able to gather, although it is still a bit of a mystery, the 3.6L has a small auxilliary12V battery that just keeps the interior operating seamlessly during a stop/start event, which is driven by the standard 12V starter battery. This would be similar to what the current Grand Cherokee has.
How?
