India to change car pollution test method from 2027: How it impacts consumers

India is set to switch to the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) for emission testing from April 1, 2027. The change applies to Bharat Stage VI (BS-VI) vehicles in the M1 and M2 categories.M1 and M2 categories cover passenger cars, SUVs, MPVs, and commercial passenger buses and vans with a gross vehicle weight below 5 tonnes. Emission tests under WLTP will be conducted on a chassis dynamometer following procedures laid down in AIS-175, as amended from time to time.

The Ministry of Road Transport and Highways notified the change through an amendment to the Central Motor Vehicles Rules. Draft norms for this shift were issued on April 28, 2025.
At present, India uses the Modified Indian Driving Cycle (MIDC) to measure both fuel efficiency and emissions. MIDC is a laboratory test based on a fixed speed-distance-time pattern. Its driving pattern is less dynamic than real traffic conditions.Both MIDC and WLTP are laboratory tests, but WLTP evaluates vehicles under conditions that better reflect real-world driving. It includes higher speeds, stronger acceleration, more varied driving phases, and shorter idling periods.

WLTP aims to narrow the gap between laboratory readings and on-road emissions of carbon dioxide (CO₂), nitrogen oxides (NOₓ), and particulate matter. The European Union adopted WLTP in 2018, and many other markets use it as a reference.

What this means for consumers

Fuel efficiency figures may appear lower: WLTP uses more demanding driving conditions than MIDC. Certified fuel economy figures may be lower than earlier MIDC values for the same vehicle. This does not mean vehicles become less efficient. It means the figures may better reflect real driving.

Emission values may better reflect road use: Reported emissions of CO₂, NOₓ, and particulate matter are expected to be closer to what vehicles produce on the road. This gives buyers data that is more representative of everyday use.

Vehicle prices could be affected: Manufacturers may need to recalibrate engines, transmissions, and emission control systems to perform under WLTP testing. These engineering changes can increase costs and may influence vehicle prices over time.

Model comparisons may change: Two vehicles that looked similar under MIDC results may show clearer differences under WLTP. Buyers may notice changes in official fuel economy labels and compliance ratings even if the vehicles themselves are only slightly updated.

Fuel-efficiency rules may align with WLTP: If CAFE norms shift as proposed, both emission compliance and fuel-efficiency targets will be based on the same WLTP test cycle.

According to the MoRTH notification, WLTP-based emission standards will apply to all new vehicle models manufactured on or after April 1, 2027. They will also apply to existing models produced from that date onward.

India implemented BS-VI emission norms nationwide in April 2020. The move to WLTP changes the testing procedure but does not change the BS-VI emission limits.

Corporate Average Fuel Efficiency (CAFE) norms also currently use MIDC. The Bureau of Energy Efficiency has proposed shifting CAFE testing to WLTP from March 31, 2027, along with the introduction of CAFE-III.