Real-world emissions performance of a Bharat Stage VI truck and bus

In-service conformity (ISC) tests for heavy-duty vehicles (HDVs) are being introduced for the first time in India with the Bharat Stage (BS) VI regulation. Such tests are meant to make manufacturers more accountable for in-use emissions and to bridge the gap between lab-based emissions and real-world emissions. While the ISC tests are not mandatory until April 2023, the requirements for testing and data processing have been established in Part IV of AIS 137 and the BS VI in-use portable emissions measurement system (PEMS) test will be performed to demonstrate compliance. At present there is little public information about the real-world emissions performance of HDVs in India, and this work aims to address that gap by conducting PEMS tests on two BS VI vehicles, one truck and one bus. ICCT conducted this work with testing partner HORIBA India.