Looking at emissions standards in Europe, a truck from 24 years ago in Europe, assuming its gross vehicle weight is between 1760 kg and 3500 kg, would be allowed to emit 0.25g of PM/km. The same limit for something built since 2013 is 0.0045g of PM/km. We're talking multiple orders of magnitude improvement here.
As a sidenote, HO+NOx has gone from 1.7g/km to 0.350g/km in 2013 (and onto 0.215g/km since then, in 2016), which is often as significant when it comes to desires to reduce air pollution.
As a sidenote, HO+NOx has gone from 1.7g/km to 0.350g/km in 2013 (and onto 0.215g/km since then, in 2016), which is often as significant when it comes to desires to reduce air pollution.