F1 fuel flow meter patent lawsuit filed in Texas days before United States Grand Prix

A patent dispute over one of the smallest parts on a Formula 1 car has reached a US federal court days before the United States Grand Prix. British company Sentronics, a former FIA supplier, has sued German rival Allengra in the US District Court for the Western District of Texas. Allengra makes the fuel flow meter that every car on the 2026 grid must use, and Sentronics says it relies on Sentronics' patented technology.

Why the fuel flow meter matters

Since the hybrid era began, F1 has limited how fast fuel can be fed to the engine. The FIA enforces this with a single specification sensor fitted to every car. The meter measures fuel flow in real time, and its data is central to checking that power units are legal. That role has become more important under the 2026 rules, which rely heavily on fuel energy limits. Those limits are set to change again in 2027 and 2028 as the balance shifts further towards the combustion engine.

According to PlanetF1, Sentronics was the FIA's exclusive supplier from 2018 to 2025. In late 2023 the FIA opened a tender for the 2026-2030 period. Allengra won it in November 2024 and became the supplier when the new regulations started this season.

What Sentronics alleges

The case centres on US Patent No. 11,391,609, which covers a fuel flow meter that sends phase-modulated ultrasonic signals through the fuel path. Sentronics applied for it in 2017, and it was granted on 19 July 2022. Allengra unveiled its own F1 fuel flow meter prototype the same month.

Sentronics says lab testing in 2024 showed that Allengra's device uses the same phase-modulation method. It says it gave Allengra written notice in August 2025 of infringement of the patent's European counterpart. It says it sent a demand letter in April 2026. It also says the FIA confirmed in September 2025 that it had received its notification. Sentronics claims the infringement has continued and is therefore wilful. It also alleges that Allengra has used its F1 contract to win work in other industries, including automotive, aviation, marine and drones.

The complaint asks for damages, including lost profits back to 2022, possible increased damages for wilful infringement, a permanent injunction and a jury trial. Neither the FIA nor Allengra had commented publicly by the time the case was reported on 20 October. None of the claims have been tested in court.

No impact on Austin

The case will not affect this weekend's race at the Circuit of the Americas. Sentronics has not asked for an emergency temporary restraining order, so the Allengra meters will be used as normal. Any wider effect would come later, either through a ruling or a settlement. If the case goes to discovery, Allengra could be required to disclose technical details such as firmware and design documents.

Filing in Texas means the dispute is being heard near the venue of one of F1's three US races. It also comes as F1 and the FIA prepare further changes to engine and fuel rules for the next two seasons.

Key takeaways

• Sentronics, the FIA's fuel flow meter supplier until 2025, has sued Allengra for patent infringement in a Texas federal court.
• Allengra won the FIA tender for 2026-2030, and its meter is fitted to every car on the current grid.
• The case concerns US Patent No. 11,391,609, granted in July 2022, which covers phase-modulated ultrasonic flow measurement.
• No restraining order has been sought, so the United States Grand Prix will go ahead as normal.

FAQ

Q: What does an F1 fuel flow meter do? A: It measures how much fuel is reaching the engine in real time, so the FIA can check that teams stay within the fuel flow and energy limits.

Q: Will the lawsuit affect the US Grand Prix? A: No. Sentronics has not requested an emergency order, so the current meters will be used in Austin.

Q: Who supplies F1's fuel flow meters now? A: Germany's Allengra, which holds the FIA contract for 2026 to 2030.

Sources: RacingNews365, PlanetF1