In a move to bridge the gap between laboratory-tested and real-world fuel efficiency, the Ministry of Road Transport and Highways (MoRTH) has issued a notification mandating that all passenger cars manufactured or imported in India must undergo fuel consumption testing with the air-conditioning (AC) system switched on. The new regulation will come into effect from October 1, 2026.
Under the proposed rules, vehicles in the M1 category (passenger cars), including both Internal Combustion Engine (ICE) vehicles and electric vehicles (EVs), will be required to test fuel efficiency (or energy consumption for EVs) with the AC operational, following the AIS-213 standard. This Indian standard specifies procedures for measuring emissions and fuel consumption while the AC is running.
What Indian government tells auto manufacturers
Manufacturers and importers will need to provide and display two sets of mileage figures:
– One with the AC switched off (current standard).
– One with the AC switched on.
These dual figures must be included in vehicle user manuals, on official websites, and potentially in other promotional materials to ensure greater transparency.
Currently, India follows European norms where fuel efficiency tests are conducted without AC usage — a condition that rarely reflects everyday driving, especially in India’s hot climate, where AC is used extensively. The AC compressor draws significant power from the engine (or battery in EVs), leading to reduced efficiency and higher fuel consumption or lower range in real-world scenarios.
Officials highlight that the change aims to deliver more closer to accurate and realistic mileage data, helping consumers make better-informed purchasing decisions. “The move is intended to reflect the conditions under which vehicles are driven on the road,” ministry sources noted, highlighting the frequent discrepancy between claimed lab figures and actual on-road performance.
Info on testing process
Tests will continue to be conducted by the Automotive Research Association of India (ARAI), the primary authority for vehicle certification and fuel efficiency validation in the country. The inclusion of AC-on testing is expected to result in lower official mileage numbers compared to current claims, as the additional load from the AC system typically reduces efficiency by a noticeable margin.
This initiative aligns with ongoing efforts by the government to enhance consumer awareness about vehicle emissions and promote realistic expectations in the automotive sector. While no specific percentage drop in mileage has been quantified in the notification, industry experts anticipate variations depending on vehicle type, engine size, and AC usage patterns.
Once implemented from October 2026, the rule will apply to all new cars rolling out from that date onward.
