The 2026 F1 season is set to introduce groundbreaking technology, and at the heart of it all is a sophisticated new monitoring system for the engines. But here's the twist: it's all about the fuel flow.
The flow meter's pivotal role
The era of turbo-hybrid F1 cars has underscored the critical and intricate role of the flow meter. By restricting fuel quantity and flow rate, manufacturers were compelled to enhance combustion efficiency, making the flow meter the linchpin in enforcing these regulations.
A new era, a new supplier
As we approach 2026, with the introduction of power units featuring a different electrical and internal combustion power split, the flow meter will undergo a significant transformation. Not only will the measurement process evolve, but the supplier will change too.
Sentronics, the long-standing supplier, equipped each car with two flow meters: one for the teams and an encrypted one for the FIA. Now, Allengra, the winner of the new technical cycle tender, will take over. This is a monumental responsibility, as the flow meter handles some of the most sensitive parameters in F1, as evidenced by the 2019 controversies that led to the FIA's decision to mandate a second meter for each car.
The evolution of the flow meter
The new flow meter is a significant upgrade, consolidating the two separate meters into one compact device. Niels Junker, Allengra's co-CEO, explains, "It's like having two units in one. The pipes' unique geometries make it mechanically challenging to synchronize them simultaneously, even with the same measurement frequency." But Allengra has a solution: different measurement frequencies on the pipes, coupled with anti-aliasing functions, thwart any synchronization attempts by the teams.
A multi-level security system
The flow meter's architecture is designed to thwart manipulation. The pipes' distinct geometries provide the first layer of protection, making synchronization mechanically difficult. The second layer involves varying measurement frequencies and anti-aliasing functions, preventing signal alignment.
The two units operate at different frequencies, and this dynamic frequency variation is crucial. Even if a team somehow synchronizes with its flow meter's frequency, replicating the encrypted unit's frequency, accessible only to the FIA in real-time, is impossible. This multi-level security system ensures the integrity of the recorded values.
A high-speed measurement system
The Allengra flow meter operates at an impressive 4-6kHz, three times faster than current sensors, performing up to 6,000 measurements per second. This speed necessitates a specialized calibration method, as conventional Coriolis sensors used by teams in factories operate at 300Hz. Allengra has developed its own 20kHz ultrasonic reference sensor for validation.
Validating the system
The system has been tested on-track in 2025. At its core is a flattened "U"-shaped structure where fuel enters, follows a path, and exits. Two ultrasonic transducers are positioned along this path, exchanging signals. The "time of flight" of these signals is crucial. Under static conditions, the system calculates the expected travel time. But when fuel flows, the signal accelerates in the direction of travel and slows in the opposite direction. By measuring these time differences and knowing the transducers' distance, the system determines fluid velocity accurately.
From volume to mass measurement
The system doesn't just measure volume, which can vary with temperature and conditions. It also measures mass, a more consistent parameter. Through fuel-specific calibrations considering density and speed of sound, the flow meter calculates mass flow rate, expressed in kilograms per hour. In 2026, this limit will drop to around 70 kg/h, reducing fuel consumption.
The flow meter's expanded role
The flow meter's role extends beyond fuel flow measurement. The Allengra sensor will also monitor an additional control parameter at the FIA's request. From 2026, the FIA will verify the energy flow rate of the fuel entering the engine. A third-party certification process will establish each fuel's characteristics and energy values per unit of mass before it reaches the track. This transforms the flow meter into a complex system that measures total fuel energy flow.
Energy density as a strategic variable
The flow meter's value in kg/h will be converted by the engine's ECU into fuel energy flow using the fuel's energy density and lower heating value, certified by a third party. The final value must not exceed 3000 MJ/h. This introduces a strategic element: the energy content of the fuel. Manufacturers with more energy-dense fuel will require less mass to achieve the same energy flow, potentially reducing on-board weight. This is fueling a development race among fuel suppliers, but there's more to the story...
What are your thoughts on this technological evolution in F1? Do you think the new flow meter system will significantly impact the sport? Share your opinions in the comments below!
