Alongside the Hyundai Creta, the only SUVs in this segment offering a diesel engine mated to a torque-converter automatic transmission (AT) are the Kia Seltos and the Tata Sierra. Where the all-new Sierra was introduced in November 2025, the second-gen Seltos entered the fray in January 2026. The Sierra diesel-AT version is limited to five trim options, but its Seltos counterpart is available in eleven. So, which one of these 5-seater midsize SUVs offers higher fuel economy?
Explore full specs, features and a price breakdown in our Seltos vs Sierra comparison.
Kia Seltos vs Tata Sierra diesel automatic: Specifications
The Sierra offers more power, but it is also heavier than the Seltos
Even though their turbocharged engines are of similar sizes, it’s the Tata Sierra’s unit that produces 2hp and 30Nm more. Moreover, the power and torque figures of these cars are achieved over the same engine RPM range. Compared to the Seltos, the Sierra diesel comes with a slightly larger fuel tank (by 3 litres), whilst the gearboxes on both are 6-speed torque-converter automatic units. Both cars are equipped with a variable-geometry turbocharger, thus improving power delivery and reducing turbo lag.
Kia Seltos vs Tata Sierra diesel automatic: Real-world fuel efficiency
Despite featuring an ‘Eco’ mode and weighing less, the Seltos fared slightly worse than the Sierra
During our real-world fuel economy test, the Seltos diesel managed an average that was 0.5kpl worse than the Sierra. It was also 0.73kpl thirstier in the city, whilst consuming 0.26kpl more fuel than its Tata rival out on the highway. Despite being heavier than a comparable diesel-automatic trim of the Seltos, the relatively lower engine RPM of the Sierra when cruising at 100kph helps its efficiency. For reference, the Seltos' diesel engine was spinning much faster at 100kph, at 2,100 RPM. Neither SUV gets an automatic engine stop-start system to reduce fuel burn further, but the Seltos does come with an Eco drive mode.
Kia Seltos vs Tata Sierra diesel automatic: Prices
The most affordable trim of the Kia Seltos diesel with the torque-converter automatic gearbox costs Rs 67,000 less than its equivalent Tata Sierra. At the top-end of the spectrum, the latter has a price advantage of Rs 53,000.
Autocar India’s fuel efficiency testing
Before our real-world fuel efficiency tests, we fill our test cars’ tanks to the brim and maintain tyre pressures based on the manufacturer’s recommendations. These cars are driven in fixed city and highway loops in and around Navi Mumbai, and we maintain certain average speeds. Throughout the tests, there is only one person in each car, running the air conditioner and other electricals, such as the audio system, indicators and wipers, when required, just like a regular user would. Periodic driver swaps further neutralise variations in driver patterns. At the end of each cycle, we calculate efficiency by filling the tanks to full again.
Prices are ex-showroom, India.
Uday Singh
Dipan Sur
Saptarshi Mondal
