In a test that should surprise nobody, the UK DfT concluded recently that all diesel cars fail the emissions standards. They tested 37 cars on the road, and despite all of then passing the NoX emissions test in lab conditions, once on the road, every one of them failed. The degree of failure varied but a 100% failure rate is enough to tell us what we already knew - the emissions tests are flawed in the same way that the gas-mileage tests are flawed.
What would be entertaining at this point would be if it turned out that of all the failing vehicles, VW were actually the smallest offenders....
The question is how to solve this? Obviously the manufacturers can't recall all their diesel vehicles - mostly because there isn't a "fix" for this issue. The only realistic solution is to raise the emissions limit and test all cars under real-world conditions, not in a lab.
Ultimately I suspect this is another nail in the coffin for diesel cars. At this point manufacturers will be pondering whether it's worth the hassle and expense of trying to pass even a new emissions standard. Honestly if I was making policy decisions for any of the large car companies, I'd abandon diesel and put the money into electric R&D instead...
DfT emissions testing program results.
