Government Mandates Air-Conditioning System Testing for Car Mileage From October 2026

The road transport ministry has issued a draft notification requiring all car manufacturers and importers to test fuel efficiency with the air-conditioning system in operation. The regulation will take effect from 1 October 2026.

Under the new rule, all cars manufactured or imported in India—including Internal Combustion Engine vehicles and electric vehicles—must be tested for fuel consumption with the AC system running. Manufacturers will be required to display mileage figures for both conditions: with and without the air-conditioning system switched on.

Also Read: Government Plans Car-to-Car Communication Mandate to Cut Road Accidents

The notification specifies that testing shall follow the AIS-213 standard, which outlines procedures for measuring vehicle emissions and fuel consumption whilst the AC operates. Officials stated the move aims to reflect the conditions under which vehicles are driven on the road.

At present, car manufacturers in India declare fuel efficiency figures based on testing conducted without the AC running. The practice follows European norms, which car makers have said does not mandate AC testing. However, officials noted that such figures often differ from the on-road performance experienced by consumers, creating a gap between claimed and experienced mileage.

The AC load substantially impacts fuel consumption and emissions. When the air-conditioning system operates, it draws power from the engine, reducing efficiency. In real-world driving conditions, the AC remains in use for extended periods, making the new testing method more representative of actual consumption patterns.

Manufacturers and importers must include the mileage data for both scenarios in vehicle user manuals and on their websites. Officials said the measure is intended to improve transparency and enable consumers to make informed purchasing decisions based on realistic fuel efficiency expectations.

The ministry is also developing a framework to increase consumer awareness of vehicle emissions. Further details on implementation will be provided through official channels.