Tata Motors has announced a new achievement for Sierra, with the 1.5L Hyperion petrol engine setting an India Book of Records benchmark by delivering 29.9 kmpl over a 12-hour run at the NATRAX facility in Indore. The test was conducted by Pixel Motion and officially certified on November 30, 2025.
This result highlights the engineering focus behind the Hyperion engine, which uses an advanced combustion system, low-friction components and a broad torque band to deliver strong efficiency and performance. The record run was completed with only brief halts for driver changes, demonstrating the engine’s consistency over extended durations.
Record Achieved Under Controlled Proving-Ground Conditions
As with most efficiency records, the feat was achieved on a closed, high-quality test track, which eliminates variables such as traffic, gradients, braking, idling, road undulations and stop-go conditions. These ideal conditions typically produce numbers far above real-world usage. Unlike public roads, there is:
• No traffic
• No braking or stop-go conditions
• No gradients or rough patches
• No idling
• No interruptions from signals, pedestrians or overtakes
For this test, Tata Sierra was driven at an avg speed of 65-70 kmph. Maintaining 65–70 kmph consistently allows the engine to operate in its most efficient RPM range, significantly improving mileage compared to real-road conditions. Tata Sierra was driven for about 800 kms over 12 hour period for this mileage test.
A Similar Test Was Done Earlier
This is not the first time a turbo-petrol SUV has posted near-30 kmpl figures at NATRAX. In 2024, the Volkswagen Taigun 1.0L TSI completed a 24-hour economy run at the same proving ground, achieving 29.8 kmpl while maintaining a steady speed of 55 kmph for over 1,300 kms.
Both results highlight that controlled, constant-speed proving ground tests can produce extremely high efficiency numbers, especially with modern turbo-petrol engines tuned for low-load cruising. Such high numbers are achievable under ideal, constant-speed proving-ground conditions, but not reflective of what customers will experience in daily city or highway use.
A Benchmark of Engine Potential, Not Real-World Mileage
The Hyperion engine’s 29.9 kmpl record should be viewed as a demonstration of efficiency capability, rather than an expectation for buyers. Official ARAI figures and real-world ownership data will paint a clearer picture of everyday fuel economy. Still, as a technical showcase, the achievement highlights Tata’s progress in petrol-engine development and adds momentum to the Sierra’s launch, especially for variants equipped with the Hyperion AT powertrain.
Speaking on this achievement, Mr. Mohan Savarkar, Chief Product Officer, Tata Motors Passenger Vehicles, said, “Setting a national efficiency record so early in the Sierra’s journey is a proud moment for us. The Hyperion engine platform was built to push the boundaries of what petrol powertrains can achieve, and this milestone validates that effort. It strengthens the Sierra’s value proposition for customers and underlines TMPV’s commitment to bringing advanced, efficient and future-ready technologies to the market.”
