Authors

T. Herrmann, P. Ochsenkühn, MAN Truck & Bus SE, Nuremberg; C. Sommer, TRATON R&D Germany GmbH, Nuremberg

Year

2026

Print Info

Production/Publication ÖVK

Summary

The emission stability of nonroad engines represents a key criterion for compliance with environmental regulations in both the European Union (EU) and the United States (USA). Currently, both markets impose extremely strict emission limits (EU-NRMM: Stage V; USA: EPA Tier 4), which must not only be demonstrated during type approval. Manufacturers are also obliged to ensure and document compliance with these limits throughout the entire specified lifetime of the engine.
Proof of emission stability is currently provided through a combination of defined test cycles, long-term emission measurements, and the use of monitoring systems such as NCD (NO_X-Control Devices) and PCD (Particulate-Control Devices). These systems continuously monitor compliance with emission limits and detect deviations at an early stage.
In practice, however, significant differences exist in regulatory requirements and test procedures between the EU and the USA. These differences lead to increased development, validation, and documentation efforts for manufacturers, as each market requires specific evidence and reporting obligations.
The aim of this paper is to systematically present the regulatory similarities and differences between these two core markets and to explain practical as well as future-oriented methods for ensuring and documenting emission stability.

ISBN

978-3-9504969-5-6

DOI

https://doi.org/10.62626/trpz-z6ad Copy link

Order Members Login