The Volkswagen emissions scandal is by far one of the most egregious acts of deceptive engineering we’ve seen in a long time. Whilst the full story of how and why it came about won’t be known for some time the realities of it are already starting to become apparent. What really intrigued me however isn’t so much the drama that has arisen out of this scandal but the engineering and science I’ve had to familiarize myself with to understand just what was going on. As it turns out there’s some quite interesting chemistry at work here and, potentially, Volkswagen have shot themselves in the foot just because they didn’t want to use too much of a particular additive:
The additive in question is called AdBlue and is comparatively cheap ($1/litre seems pretty common) when compared to other fluids that most modern cars require. The problem that Volkswagen appears to have faced was that they didn’t have the time or resources require to retrofit certain models with the system when it became apparent that they couldn’t meet emissions standards. As to why they chose to defeat the emissions testing devices instead of simply delaying a model release (a bad, but much better, situation than what they currently find themselves in) is something we probably won’t know for a while.
Regardless it was an interesting aside to the larger scandal as I wasn’t familiar with this kind of diesel technology previously. Indeed now that I understand it the scandal seems all the more absurd as the additive is cheap, the technology well known and has successful implementations in many other vehicles. Still it introduced me to some interesting engineering and science that I wasn’t privy to before, so there is that at least.