I purchased new 2014 Durango (6 cyl.) about a month ago. The shifting when I accelerate from a stop is very erratic. Sometimes it shifts fine, but sometimes it feels like it went into too high of a gear and stops accelerating. When I give it more gas, it feels like it shifts to a lower gear and takes-off unexpectedly. I cannot seem to predict to what it is going to do. Is this typical of what everyone else is experiencing with the new 8 speed transmission and I just need to get used to it and live with it?