India To Adopt WLTP Testing Under BS-VI From 2027

In a significant step toward strengthening vehicle emission monitoring, the Indian government has notified the adoption of the Worldwide Harmonised Light-duty Vehicles Test Procedure (WLTP) for testing emissions under Bharat Stage VI (BS-VI) norms. This new testing framework will come into effect from April 1, 2027, and will apply to Category M1 and M2 vehicles, including passenger cars, SUVs, MPVs, and commercial passenger vehicles with a gross vehicle weight (GVW) of up to 5 tonnes.

The decision is aimed at making emission testing more aligned with real-world driving conditions, addressing concerns that existing laboratory-based tests do not accurately reflect actual on-road vehicle performance.

Legal Amendment to Enable WLTP Testing

To formalise this transition, the government has amended the Central Motor Vehicles Rules, 1989. The Ministry of Road Transport and Highways had first issued draft norms on April 28, 2025, outlining the shift to WLTP. Following stakeholder consultations and regulatory review, the final notification has now been issued.

Under the revised rules, all new vehicle models manufactured on or after April 1, 2027, must comply with WLTP-based emission testing. Additionally, existing models will also need to meet the new testing standards from the same date onwards.

From MIDC to WLTP: What Changes?

Currently, India uses the Modified Indian Driving Cycle (MIDC) as the standard speed-distance-time map for testing both fuel efficiency and emissions. However, MIDC has been criticised for not accurately representing real-world driving patterns, leading to discrepancies between laboratory test results and actual emissions.

WLTP, which has been in use in the European Union since 2018, is considered a more rigorous and realistic testing cycle. It factors in varied driving conditions, higher speeds, longer distances, and more dynamic acceleration patterns. This ensures that emissions of pollutants such as carbon dioxide (CO₂), nitrogen oxides (NOx), and particulate matter (PM) measured in labs are closer to real-world levels.

How the New Tests Will Be Conducted

Under the new framework, WLTP-based emission testing will be carried out using a chassis dynamometer. The procedures will follow the guidelines laid out in Automotive Industry Standard (AIS)-175, as amended periodically.

This means vehicles will be tested under controlled conditions that better simulate actual driving scenarios, improving the reliability and credibility of emission data.

Alignment with India’s BS-VI and CAFE Roadmap

India implemented BS-VI emission norms nationwide in April 2020, marking a major leap toward cleaner mobility. The shift to WLTP-based testing does not change the existing BS-VI emission limits but ensures that compliance is assessed more accurately.

Separately, Corporate Average Fuel Economy (CAFE) norms in India currently rely on MIDC for efficiency testing. However, the Bureau of Energy Efficiency has proposed transitioning to WLTP under the upcoming CAFE-III framework from March 31, 2027. This suggests a broader regulatory shift toward globally aligned testing standards.

What This Means for Automakers and Consumers

For automakers, the transition to WLTP will require adjustments in vehicle calibration, engine tuning, and emission control systems. Some models may need technical upgrades to meet stricter real-world performance criteria.

For consumers, this move is expected to result in more transparent emission figures and potentially better fuel efficiency reporting, helping buyers make more informed decisions.

Overall, India’s adoption of WLTP marks a progressive step toward cleaner, more accountable, and globally harmonised vehicle emission standards.