Aftertreatment gets burned.

The article reports on how diesel passenger cars will keep within a strict limit of 80 milligram per kilometer of nitrogen oxide (NOx) in Europe. It states that diesel's raw NOx emissions are already quite low because of the dual-stage sequential turbocharging and cooled exhaust gas recirculation. However, additional hardware such as cylinder pressure sensors and variable valvetrains that use sophisticated control algorithms may be needed.