I think the recent technological development of the modern diesel is pretty impressive. Environmental policies set the bar at 120g&#x2F;km and all the manufacturers promptly delivered on that. The engine power inflation didn&#x27;t even stop (on the contrary, it continued) so now we drive super-efficient and super powerful small engines. 200hp, 300Nm and 5L&#x2F;100km would seem like sorcery 15 years ago. Now it&#x27;s par for the course.<p>This would seem like a massive success for environmental regulation, and then the VW scandal broke. To me it just seems that the regulation wasn&#x27;t good enough: all it would have taken was to have strict regulations for <i>all</i> emissions (Particles, CO2, NOx, ...) and realistic test cycles.<p>At this point we should probably just tighten the regulations: set the bar at 100g&#x2F;CO2 and also tighten the other emissions values to whatever a modern 1.4Litre petrol engine emits today. Then tighten the regulations every year. If manufacturers can squeeze diesels down to those levels, great! If they can&#x27;t, hybrids and EV&#x27;s will take the place of these cars that consumers will likely find underpowered under the new emission standards.