Re: 2011/12 Hemi grand cherokee exhaust
I don't know what the HP, torque or MPG gains are, would depend on what you replaced it with. But the stock exhaust is 2.5" to the ball flanges in the middle, from there it is 2.25" the rest of the way.
2012 Hemi Overland
2005 HD Springer Softail Classic