The cost is much higher for those diesel engines, hence why they didn't offer it for the little, inexpensive Jeeps.
In the 2014 Grand Cherokee, the 5.7L HEMI is a $2300 option. The smaller 3.0L six cylinder diesel (that makes a bit more torque than the HEMI and gets lows 20s in town and high 20s on the highway) is a $4500 option.
[COLOR="Silver"][B][SIZE="3"]2012 Jeep Compass Sport 4x4[/SIZE][/B][/COLOR]
[I]2.4L I4, CVT II, Freedom Drive I[/I]
[COLOR="DarkSlateGray"][B][SIZE="3"]2010 Dodge Dakota Quad Cab 4x4[/SIZE][/B][/COLOR]
[I]4.7L V8, 545RFE, Big Horn Edition[/I]