> The UK government permits new cars to be sold with tailpipe emissions which are VASTLY higher than those of comparable vehicles in the USA. What I could find

> The UK government permits new cars to be sold with tailpipe emissions which are VASTLY higher than those of comparable vehicles in the USA. What I could find about the latest standards does not seem to support your claim. But maybe I'm looking at wrong numbers or misinterpreting them, so I wouldn't mind looking at your own sources if you have them. EURO 6d standards for diesel passenger cars [1]: - CO: 0.5 g/km - NOx: 0.080 g/km - PM: 0.0045 g/km California LEV standards for passenger cars <50K miles/5 years [2]. (Not the same as EPA, but I assume California is more strict): - CO: 3.4 g/mi = 2.1 g/km - NOx: 0.2 g/mi = 0.12 g/km - PM: 0.08 g/mi = 0.05 g/km [1] https://en.wikipedia.org/wiki/European_emission_standards https://en.wikipedia.org/wiki/European_emission_standards [2] https://www.dieselnet.com/standards/us/ld_ca.php https://www.dieselnet.com/standards/us/ld_ca.php