Since the report discusses Jeep Grand Cherokees, and that engine is also available in the Ram 1500, it's safe to assume that one of the implicated engines is the EcoDiesel V6, a unit actually produced by VM Motori. It's unclear whether the report covers any of the Cummins engines used in heavier-duty Ram pickups.
This report comes on the heels of a federal investigation into FCA's diesel vehicles. That investigation focused on the EcoDiesel engine used in 2014-2016 vehicles. The feds were seeking a fine of up to $4.6 billion. The EPA and the State of California also previously accused FCA of using a defeat device on the same vehicles back in January.
FCA, for its part, alleges that the WVU study might have been commissioned by people interested in suing the company, and disputes the testing methodology, according to the WSJ.
We've reached out to WVU to confirm which engines are implicated in its study and will update this post when we have more to share.