WLTP to be used for BS-VI emission testing from 2027
What's the story
The Indian government has announced the adoption of the Worldwide Harmonized Light-duty Vehicles Test Procedure (WLTP) for Bharat Stage VI (BS-VI) emission testing. The change will come into effect from April 1, 2027. The new procedure will be applicable to M1 and M2 category vehicles, which include passenger cars, SUVs, multi-purpose vehicles, as well as commercial passenger buses and vans with a gross vehicle weight (GVW) of less than five tons.
Testing evolution
What is the WLTP?
The WLTP is a more realistic cycle for measuring vehicle emissions, as compared to the older lab-based test cycles. It was adopted by the European Union in 2018 and ensures that carbon dioxide, nitrogen oxides, and particulate matter emissions from vehicles on road are closer to those recorded in laboratory conditions. The current speed-distance-time map for testing fuel efficiency and emissions norms in India is the Modified Indian Driving Cycle (MIDC).
Compliance timeline
WLTP will replace existing test cycles
The amended rules mandate that all new vehicle models manufactured on or after April 1, 2027, must comply with the revised WLTP-based emission standards. The same goes for existing models from that date onward. Emission tests under WLTP will be conducted on a chassis dynamometer as per the procedures laid down in AIS-175, as amended from time to time.
Norms implementation
Transition to WLTP in line with global practices
India implemented the BS-VI emission norms across the country in April 2020, a major step toward tightening vehicle emission standards. The move to WLTP-based testing is expected to make emission measurements more representative of on-road driving conditions while keeping the existing BS-VI emission limits intact. The Bureau of Energy Efficiency has also proposed a shift from MIDC to WLTP cycle from March 31, 2027, with the introduction of CAFE-III.