I have driven the '11 Grand Cherokee, Caravan, and Avenger all with the new Penstar. Love it compared to '10 models.

 

Look at it this way; it can't possibly be any worse than the 3.8. So see, only place to go in performance is up..

 

I too just rented a 2011 Dodge Caravan with the new 3.6 ltr for a trip from IL to FL and I must say that it was pretty impressive. I was able to get 24 MPG on the hwy loaded down and the power was a definite improvement over my 3.8 ltr.

The only thing I noticed was that the van liked to down shift from the high gear on the slightest incline.

Probably not the same set up the JK would get but it sure gave me hope! Anxiously awaiting the actual set up and specs on the 2012 JK....

 

Thanks for the info.
I have never been able to get anything better than 17 mpg in my 08 Grand Cherokee so 18.7 would work fine for me.