I take those Wards Best Engine rankings with a grain of salt. The 3.6 Pentastar was ranked in the top 10 in 2012 with all of the cylinder head problems.

 

I'd even take a VM2.8CRD [currently available outside North America] in a Rubicon, but I'd prefer the 3.0 EcoDiesel.

Whoever named that engine in Chrysler did not do their research very well. VW had ECOdiesel 4cylinder engines in the early '90s. Those were the slow, shaky, rattly, smoky diesels that gave 50+MPG's on the Jettas & Rabbits.