Mileage testing with AC to be mandatory for cars from October 2026

New Delhi: The Ministry of Road Transport and Highways has proposed mandatory testing of vehicle fuel efficiency with the air-conditioning (AC) system both switched on and off, in a move aimed at providing more realistic mileage figures to consumers, according to a Times of India report.

Under the draft notification issued on Thursday, the requirement will apply to all passenger cars (M1 category), including internal combustion engine (ICE) vehicles and electric vehicles (EVs), manufactured or imported in India on or after October 1, 2026. The notification states that such vehicles “shall be tested for measurement of fuel consumption with air-conditioning system in operation, as per AIS-213, as amended from time to time”.

Officials said car manufacturers and importers will subsequently be required to disclose mileage figures with and without AC usage in vehicle user manuals and on their websites. At present, automakers in India declare fuel-efficiency figures based on tests conducted without the AC running, citing alignment with European norms.


According to officials, the proposed change is intended to better reflect real-world driving conditions, as AC usage has a significant impact on fuel consumption and energy efficiency. They noted that mileage figures declared without AC often differ from on-road performance experienced by consumers.

AIS-213 prescribes detailed procedures for measuring fuel consumption and emissions with the AC system operational, factoring in the additional load imposed by air-conditioning. This can materially affect both efficiency and emissions levels.

The ministry is also working on a broader framework to enhance consumer awareness on vehicle emissions, and may, in future, require more detailed disclosures for car buyers, the Times of India report said.

With inputs from TOI