The issue appears to be, that lab testing does not emulate real-world driving conditions. So in the field, emissions are higher than in the lab.<p>These four car makers involved in the report differ from VW: they <i>do not</i> have a defeat device in their design. Their results are solely because of the lab-vs-road issue.<p>Its not clear this is any kind of problem. Reducing emissions in lab tests may very well result in car designs that have reduced road emissions. That was the hope when lab standards were introduced. Auto pollution in our cities has indeed gone down as (lab) emissions standards have been tightened over the years.