Mine has the dual rear exhaust. Sounds nice at idle, and also under acceleration. I must admit that I was a bit disappointed that Dodge didn't run true dual exhaust. Plenty of room under there for that. I can say that the pipe running from the y-pipe to the muffler is HUGE, like maybe 4 inches in diameter. But still, I think the truck would have benefitted from true dual exhaust.

So, the only tune available would necessitate running premium fuel?