Tata Motors launched the new Sierra SUV in November 2025, but one key detail was never officially revealed – the ARAI-certified mileage figures. Now, thanks to an RTI filed by Twitter user Vahan Warta, these fuel efficiency numbers have finally been revealed.
As per the RTI response received from ARAI, the 1.5L TGDi Hyperion petrol engine delivers 13.5 kmpl, while the 1.5L Kryojet diesel delivers 18.8 kmpl. Interestingly, the 1.5L naturally aspirated petrol variant has still not been issued ARAI certificate. The diesel engine received ARAI certification on 21 November 2025, while the turbo petrol engine was certified on 11 December 2025 – both around the time of the Sierra’s launch window.
Mileage figures and certification details
As per RTI response:
1. 1.5L NA Petrol – Certification not yet issued
2. 1.5L TGDi Hyperion Petrol – 13.5 km/l (Certified on 11.12.2025)
3. 1.5 L Cryojet Diesel – 18.8 kmpl (certified on 21.11.2025)
Interestingly, at the time of launch, Tata Motors had highlighted the mileage-related marketing claim for the Sierra’s 1.5L Hyperion petrol engine. The company announced that the achievement of 29.9 kmpl achieved during a 12-hour run at the NATRAX Proving Ground in Indore has entered the India Book of Records.
Strong demand since launch
Despite the absence of officially published mileage figures, the Tata Sierra has seen strong demand since its launch. Deliveries began on January 15, 2026, and the company recently confirmed crossing the 10,000 unit delivery mark in just a few weeks.
The SUV had already generated massive interest, with bookings crossing 70,000 units within 24 hours and later crossing the 1 lakh mark. This indicates that buyer interest remains strong even without full transparency on some specifications.
Production and expansion plans
Tata Motors is currently focusing on increasing production to meet the growing demand. The Sierra is being manufactured at the Sanand facility along with the Nexon. Production is expected to reach approximately 15,000 units per month in the coming months. Along with the ICE variant, Tata is also preparing to launch the Sierra EV, which is expected to arrive by June 2026.
While the Sierra continues to post strong sales momentum, the delayed disclosure of ARAI mileage figures raises concerns over transparency. In a market like India where fuel efficiency plays a major role in purchasing decisions, such details are usually highlighted early on. The RTI response now fills that gap – albeit months after the SUV was launched and delivered to customers.