Industry paper Automotive News reports the same testing used on Volkswagen diesel models has revealed emissions up to 20 times above legal limits in some FCA diesel-powered vehicles.
The research group is from West Virginia University, and the latest testing was sparked when US authorities expressed a belief that emissions ‘defeat devices’ or similar may be in use by other carmakers.
"We saw emissions results in simulated on-road cycles on chassis dynamometers that were much lower than the actual on-road results were, suggesting that the vehicle was controlled in different fashions," West Virginia University’s Centre For Alternative Fuels’ Daniel Carder said.
Using five Jeep Grand Cherokees and five RAM 1500 pickups - each from the 2014-15 model-years - the university measured nitrogen oxide (NOx) levels in a laboratory environment and then again using portable equipment during ‘real world’ driving.
While the university has not accused Fiat Chrysler of any wrongdoing, the researchers claim NOx measurements during real world driving exceeded those permitted by US clean air laws and were higher than the lab test results.
In a statement, Fiat Chrysler reportedly claimed that the research was commissioned by the US Justice Department as it pursues a civil court case against FCA. When asked, Mr Carder reportedly declined to say whether any one has commissioned the research.
FCA also reiterated that US emissions testing does not take place on public roads, suggesting that researchers may have carried excess weight or used harsh acceleration to manipulate the results.
Mr Carder responded, however, saying that the test route included a steep ascending road and commenting "we were seeing elevated NOx levels even on the ascent, which is something we wouldn’t expect."
FCA said its position remains that it has not operated outside the rules, particularly adamant that it has not used any sort of ‘defeat device’.
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