Based on the drafts from EU Council and Parliament Committees the initial plan to introduce Euro 7 by 2027 for commercial vehicles, under consideration of extended boundary conditions and significantly reduced pollutant emission levels, was discarded. Besides an effort increase related to on board monitoring (OBM), pollutant emission limit reduction is less than initially expected and the evaluation boundary conditions are similar as in force for Euro VI-E. Independent from the regulation process in the EU, the EPA will set stringent emission standards for heavy-duty vehicles and engines starting in 2027. The proposed rule is a federal counterpart of the California low NOx regulation. It introduces lower NOx and PM emission standards for heavy-duty engines. This includes standards for the existing laboratory test cycles, as well as new standards based on the Low Load Cycle (LLC) and off-cycle emission limits. 0.035 g/bhp-hr NOx(in SET & FTP) represents an 82.5% reduction in NOx emissions compared to the current legislative limits. In the off-road sector introduction of Tier 5 in California for NRMM between 2029 and 2033 is discussed. The Tier 5 proposal is set up with an interim and final state and it’s targeting a significant reduction of PM emissions which mandates the introduction of a particle filter in the exhaust aftertreatment system, including of a low load cycle and idling standard for NOx emissions. Additionally, for the final phase, which is planned from 2033 onwards, a NOx reduction of 90% is targeted. Furthermore, the Tier 5 rulemaking workgroup proposes the introduction of OBMD (On-Board Monitoring & Diagnostics). AVL will show commercial engine and aftertreatment concepts, for different legislative scenarios in the EU & NA and possibilities for communality. Further on the main challenges for OBD monitoring and AVLs approach for robust fault detection and improved monitoring frequency in the field are being discussed.