Tim and George chat to Jack Riddle and Volker Brichzin from Purem by Eberspaecher about technologies to meet upcoming ultra-low NOx requirements at low-load and idling while meeting packaging, back-pressure and durability requirements – including compact urea mixers for dual dosing, hydrocarbon mixers and electrical heating options – in an environment where OEMs are selecting powertrain options such as stop-start, cylinder deactivation and hybridisation. We discuss the implications of the next round of regulations, which aim to broaden requirements beyond traditional test cycles to ensure compliance across a much wider range of operating conditions. We also discuss opportunities for hydrogen internal combustion engines and the potential aftertreatment requirements with much higher exhaust water content.