Fiat Chrysler Automobiles (FCA) is responding to an alleged claim around some on-road testing of emissions on a couple of the company’s diesel models near West Virginia University.

MSN reported that the FCA obtained court filings and communicated with the University’s Center for Alternative Fuels Engines and Emissions (CAFEE). The company believes CAFEE’s testing was launched by a plaintiff within the lawsuit against FCA regarding discrepancies in emissions of its RAM 1500 pickup and Jeep Grand Cherokee SUV.

It is being reported that Fiat Chrysler requested that CAFEE share the methodology around testing and subsequent data, however, it is also being reported that this was refused; with CAFEE stating that testing could be compared to five required laboratory tests from the Environment Protection Agency (EPA). FCA is stating that the organization underwent testing at speeds that were 50% more than that of lab tests by the EPA, with exceeding EPA payload by 272-317 kg. Additionally, the roads apparently did not represent virtual EPA evaluations.

FCA has also claimed that each of these elements can have a negative and direct effect when it comes to emissions, with all of them together marking a worse change. Therefore, FCA believes these results are misleading and invalid. The company also claims that those models that did the testing were modified in an effort to replicate an earlier recall the FCA conducted.

Ram diesels and Grand Cherokee recently underwent a software update this year, which also happen to be the models that CAFEE tested, and in May of the company placed forth an application for certification from the California Air Resources Board (CARB) and EPA regarding their latest cars for the year. They also asked for permission to place updated systems and software in their 2014 to 2016 Rams and Jeeps that are undergoing an investigation around emissions readings that came out false.