Government Mileage Testing With AC On and Off in India Explained

Mileage claims have always felt slightly optimistic to Indian car buyers. The Ministry of Road Transport and Highways has finally acknowledged this gap. From October 1, 2026, mileage testing with AC on and off in India will become mandatory for all vehicles sold in the country.

This move aims to reduce the difference between claimed fuel efficiency and real world mileage that buyers actually experience on Indian roads.

What the New AC Mileage Testing Rule Actually Says

As per the draft notification, every car manufacturer and importer must test fuel efficiency under two conditions. One with the air conditioning switched off and another with the air conditioning switched on.

This regulation applies across all powertrains including petrol, diesel, CNG, hybrid, and electric vehicles. Carmakers must publicly declare both mileage figures, making mileage testing with AC on and off transparent for buyers. Currently, official mileage testing happens only without AC, which often leads to unrealistic expectations.

Why the Government Is Changing Mileage Testing Norms

India is not Europe. Most cars here run with AC switched on for a majority of their lifecycle due to climate, traffic congestion, and urban driving conditions.

In petrol and diesel cars, the AC compressor adds load on the engine, increasing fuel consumption. In electric vehicles, AC usage directly reduces battery range.

Officials believe mileage testing with AC on and off will better reflect real world efficiency and help buyers plan running costs more accurately.

How Mileage Figures Are Expected to Change After October 2026

Mileage numbers are unlikely to look better on paper, but they will be more honest.

Mileage testing with AC on and off will align claimed numbers closer to daily driving experience.

What This Means for Indian Car Buyers

Buyers will now see two efficiency figures instead of one. Mileage with AC off and mileage with AC on.

This clarity helps compare cars fairly, especially in budget segments where fuel costs matter the most. It also prevents disappointment after purchase, since expectations are grounded in real usage conditions.

Mileage testing with AC on and off essentially shifts power from marketing brochures to informed decision making.

How Carmakers Must Comply With AIS 213 Standards

Manufacturers must conduct testing as per AIS 213, which defines procedures for emissions and fuel consumption with AC operating.

These figures must be published across brochures, official websites, owner manuals, and customer facing material. This ensures consistency and prevents selective disclosure. The shift marks India moving away from Europe focused test cycles to climate specific regulations.

Will This Completely Solve Mileage Confusion

Not entirely. Real world mileage still depends on driving style, load, traffic, road conditions, and maintenance.

However, mileage testing with AC on and off removes one major blind spot. Buyers will finally understand how much AC usage actually costs them.

FAQs

When will mileage testing with AC on and off become mandatory in India
The rule is proposed to come into force from October 1, 2026.

Does this rule apply to electric vehicles
Yes. Electric vehicles must also declare range figures with AC switched on and off.

Will car prices increase because of this rule
Testing costs may increase slightly, but no direct price hike has been announced yet.

Why was mileage earlier tested without AC
India followed European test cycles, where AC usage is less frequent compared to Indian conditions.

Will real world mileage still vary
Yes. Factors like driving habits, traffic, weather, and vehicle load still affect fuel efficiency.