This is pretty much how the defeat was discovered - by a group who were curious about how US diesels could be so great compared to their European counterparts, using sniffers attached to vehicles performing normal road driving.
Unfortunately, this wouldn't work very well as a certification test, as it would require standardization. But, as a failsafe in addition to a standardized test plan, I think this would be great - basically "we'll give you the procedural test you know and love, and we'll drive 100 normal road miles with more lenient thresholds in place. Fail either and you don't get a certification."
Unfortunately, this wouldn't work very well as a certification test, as it would require standardization. But, as a failsafe in addition to a standardized test plan, I think this would be great - basically "we'll give you the procedural test you know and love, and we'll drive 100 normal road miles with more lenient thresholds in place. Fail either and you don't get a certification."