Who's planning on making the move to a diesel JK? The story is that the 2016 model year will have the 3.0L diesel as an option. The question is... is it worth it? In the 2015 Grand Cherokee (and Ram 1500), it's rated at 240HP/420TQ. It's rated at 30mpg highway for the Grand and 28mpg for the Ram 1500. I've read that it really does get that 28mpg performance in the pickup... but, the aerodynamics of the JK are worse so I dunno how that'll relate.
So, the numbers look good, especially that 420ft-lbs of torque. But, it's a $4500 option to switch from the 3.6L gas engine to the diesel in the Grand Cherokee and $4000 for the Ram 1500. Those numbers don't look that great.
I've been wanting to get a 2017 Jeep JL (new generation) with a diesel, but for a $4000 premium... I dunno. The JL will have a little better aerodynamics so even the gas engine should get better gas mileage.