What are we down to now? 70%? 80%? of original performance with all the mitigations added up by now? If a car was advertised as emitting 20% less pollution tha

What are we down to now? 70%? 80%? of original performance with all the mitigations added up by now? If a car was advertised as emitting 20% less pollution than it actually did, people would be pissed[1]! [1]: https://en.wikipedia.org/wiki/Volkswagen_emissions_scandal https://en.wikipedia.org/wiki/Volkswagen_emissions_scandal