The official mileage figures of Tata Motors' popular mid-size SUV Tata Sierra have finally become public. Information received from ARAI (Automotive Research Association of India) through an RTI (Right to Information) application, several months after its launch in November 2025, has revealed that the 1.5 liter turbo petrol engine and 1.5 liter diesel engine give much less mileage than the claims made by the company.
Tata Sierra was originally introduced in the 1990s and was considered an iconic SUV in the Indian automobile market. The company revived it as a completely new generation in 2025. The new Sierra has modern design, advanced features and two powertrain options – 1.5L TGDi Hyperion turbocharged petrol engine and 1.5L Kryojet diesel engine. At the same time, it also gets 1.5 liter NA petrol engine.
Tata Sierra exposed!
At the time of launch, the company had marketed the Sierra as having a good balance of mileage and performance, but the official ARAI certified mileage figures were deliberately not made public. For this reason a person filed RTI and asked for data from ARAI. The information received in response to RTI is now going viral on social media and auto websites.
According to the data revealed by RTI, the ARAI mileage of 1.5 liter turbo petrol variant is 13.5 kilometers per liter. Whereas, 1.5 liter diesel variant gives a mileage of 18.8 kmpl. The mileage of the naturally aspirated (NA) petrol engine has not been certified yet. These figures are based on the standard ARAI testing cycle, which takes into account mixed city and highway driving. In the real world, mileage depends on driving style, traffic, load and maintenance.
What did the company say?
After the launch, Tata Motors conducted a special test run of Sierra on NATRAX track (Indore), in which the company claimed a mileage of 29.9 kmpl. This test was done at constant speed (65-70 kmph) and ideal conditions, so it is very different from normal driving or ARAI certification. When the mileage received from RTI was much lower than these claims, auto experts said that the NATRAX record was only for marketing and the actual user experience would be closer to ARAI figures.
Price and competition
The price of Tata Sierra is approximately between Rs 13 to 25 lakh (ex-showroom). It competes with vehicles like Hyundai Creta and Kia Seltos in the segment. Sierra has been provided with features like 5-star GNCAP safety rating, Advanced Driver Assistance System (ADAS), panoramic sunroof, ventilated seats, 360 degree camera and large touchscreen infotainment system. Its design is retro-modern, reminiscent of the old Sierra but meeting the needs of the new generation.
Good economy of diesel engine
The mileage of 18.8 kmpl is good news for buyers choosing the diesel variant, as the diesel engine proves to be more economical on long drives and on the highway. At the same time, petrol variant is more convenient for city driving but fuel expenses may increase due to low mileage.
If an average user drives 15,000 kilometers in a year, the fuel cost on petrol variants can be much higher than diesel. For example, if the price of petrol is Rs 95/litre and diesel is Rs 85/litre, then the annual savings can be thousands of rupees.