Published : 25 June 2026
Read Time : 5 min
Author: Navneet Kumar
In this article, we’ll present the data based on V3Cars mileage test and inform you about what real-world fuel efficiency you can expect from the Tata Sierra 1.5L turbo diesel-automatic in city and highway driving conditions. We’ll also find out how much the mileage numbers deviate from the manufacturer-claimed fuel efficiency figures. The information presented in this article will also help you learn about the mileage differences you can expect when driving in the city vs driving on the highway.

Before we provide the actual mileage of the Tata Sierra 1.5L turbo diesel-automatic, let's briefly explain our testing process so that you can decide if it matches your preferences, style and conditions for driving.
We use the tank-full-to-tank-full method for our real-world fuel efficiency tests. First, we fill the fuel tank to the brim, reset the trip metre, and then begin our ~100km city drive in Delhi NCR traffic. The test is conducted on the same route during weekdays to simulate realistic city driving conditions, while maintaining the same load to keep the results consistent.
For both city and highway runs, the vehicle is driven in its Normal drive mode, where available, since our goal is not to extract the highest possible fuel efficiency figures, but to evaluate how the car is likely to perform for most drivers in everyday driving situations.
Once the city run is complete, we return to the fuel station, refill the tank to the same level and note the fuel consumed to calculate the city mileage. We then reset the trip metre before starting the highway mileage test. For the highway run, we choose the stretch around Sohna along the Delhi-Mumbai expressway and we drive it for 100km at a cruising speed of around 100kmph. Then, we refill and note down the trip metre readings to calculate the highway mileage figure.
For fuel prices, we assume a flat cost of Rs. 105.00 per litre for petrol, Rs. 100.00 per litre for diesel and Rs. 95.00 for CNG. This is done to bring our calculations and cost-per-km estimations closer to a national average price of the respective fuel type. For instance, using a very low price of CNG, as applicable in Delhi, skews the final verdict in favour of CNG vehicles even though CNG is quite expensive in most states.
After driving the Sierra in the city traffic for about 4 hrs 30 mins, we drove back to the fuel station. We covered 102.7km with an average speed of 22.82kmph. During refuelling, we were able to fill up 10.32 litres of diesel in the Sierra at a per litre diesel price of Rs. 100.00. Thus, the total bill stood at Rs. 1,032.00 and in our real-world city mileage test of Sierra 1.5l turbo diesel-automatic, we got a final fuel efficiency figure of 9.95kmpl.
With the tank filled to the brim once again, we headed out on the Delhi-Mumbai expressway to test the highway mileage of the Sierra 1.5l turbo diesel-automatic. We managed to complete our 110.5km drive in about 1 hrs 30 mins, meaning our average speed during the highway mileage test of the Sierra was 73.67kmph. After the drive, we filled up 5.17 litres of Diesel, incurring a bill of Rs. 517.00 if you assume a fuel price of Rs. 100.00 per litre. During our highway run of the Tata Sierra with the diesel-automatic, we achieved a highway mileage of 21.37kmpl.
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Based on our mileage test, the Sierra diesel-automatic gave us a city mileage of 9.95kmpl. On the highways, you can expect this figure to jump up by 114.77% to 21.37kmpl, as we saw in our Sierra mileage test.
Compared to the official claimed mileage figure of the Sierra diesel-automatic, our Sierra diesel-automatic city mileage turned out to be 9.27kmpl less efficient. Thus, showing a 48.23% deviation from the claimed figure. With this fuel efficiency, you can expect to incur a per kilometre fuel cost of Rs. 10.05 if you drive mostly in the city traffic with a fuel cost of Rs. 100.00.
In terms of highway mileage, we achieved a figure of 21.37kmpl with the Sierra we drove. This number of 2.15kmpl is more than the claimed mileage figure. Thus, the deviation in the highway mileage of the Sierra diesel-automatic is about 11.19% on the positive side. At this rate, you can expect to spend Rs. 4.68 per kilometre for predominantly highway driving during the ownership.
If your driving happens entirely on the highways or just within the city, then you know what mileage you can expect from the Tata Sierra diesel-automatic. However, for those who have a mixed usage, we have compiled combinations of effective mileage of Sierra diesel-automatic based on the variations of city-highway driving ratio.
Using this customised city-highway combinations, you can better gauge what fuel costs and realistic fuel efficiency you can expect from the Sierra with the Diesel-Automatic powertrain.
*City mileage: 9.95kmpl; Highway mileage: 21.37kmpl
*To accommodate varying fuel prices across the country, and to make the cost per kilometer information a bit more relevant for a larger number of potential car buyers, we are assuming a fixed fuel cost of Rs. 105.00 per litre for petrol and Rs. 100.00 per litre for diesel
Based on these combinations, for a 70% city and 30% highway usage, you can expect a real world mileage of 13.38kmpl and a per kilometre fuel cost of Rs. 7.48 from the Sierra. With a flipped combination, where you drive the Sierra 70% on the highways and 30% in the city, you should expect your real-world mileage figure to hover around 17.94kmpl with fuel costs around Rs. 5.57.
For an even split of city and highway usage, your real fuel efficiency with the Sierra 1.5L turbo diesel-automatic powertrain, your effective real mileage is likely to be closer to 15.66kmpl. Thus, your per kilometre fuel costs could be around Rs. 6.39.
The Tata Sierra with the 1.5L turbo diesel-automatic comes with a 50-litre fuel tank. With this capacity and our realistic mileage estimates, you can expect to get a range of 448 - 962 km depending on whether your driving is entirely within the city or on the highways.
With a 70-30 driving split in favour of city usage, you can expect a full tank range of 602km from the Sierra. However, if you flip the driving condition to 30-70 in favour of highway, then you can expect a range of 807km with a full tank of fuel. On an even split of 50% city driving and 50% highway driving, you will have to refuel about every 705km.
*Tank range estimated based on 90% fuel usage with 10% remaining in reserve
At the time of testing the Tata Sierra 1.5L turbo diesel automatic, each refuelling will cost you Rs. 4,500.00 if you fill up 90%. This is assuming the fuel cost of Rs. 100.00 per litre of diesel.
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Web Content Writer
Navneet is drawn to systems that work with clarity and purpose—clean, efficient, and built to last. He values solutions that feel intuitive and seamless, even if the effort behind them is anything but simple.

























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