How to read the Actual Fuel Efficiency and Mileage of your Car?

Government regulations mandate that for every vehicle sold, the manufacture has to clearly define the claimed fuel efficiency. This claimed fuel efficiency carries a certification from the Government Of India authorized ARAI (Automobile Research Authority of India).

However, almost all of us never ever get the fuel efficiency that has been certified by ARAI.

Why is that? What is the actual fuel Efficiency that we need to expect?

Readers would recollect the recent case when the Country's largest selling EV car, the Tata Nexon was delisted by the Delhi Government from the subsidy it offered for EV Cars, as the Tata Nexon could not deliver on the mileage it offered in real-time conditions.

The issue had arisen due to a customer raising a complaint that against the state mileage of 312 km on a single car, his Tata Nexon had given only 200km. He reached out to the Delhi Government, which then delisted the Nexon.

Tata motors challenged the delisting in the Delhi High Court but could not get a satisfactory response.

Tata Motors challenge was:” The range at single full charge (312km) for the Nexon EV is basis the certification received from the Automotive Research Association of India (ARAI), which is the official body that independently tests all mass-produced vehicles under standard/defined test conditions before they can be offered to customers.

The actual range is dependant on individual driving style and the actual conditions in which the car is driven. It is also a function of the familiarity with the new technology, and customers report improvement upwards of 10% within 4-6 weeks of familiarity.”

For the ICE technology vehicles, ARAI does not perform actual tests but uses a Chassis Dynamometer to replicate road conditions.

Taking all these conditions, the thumb rule for actual mileage is to allow for 20% loss from the Claimed Mileage. So, if the manufacturer claims a mileage of 20Kmpl, the actual mileage would be 16Kmpl.