A dispute about the design used by the FIA’s exclusive fuel flow meter supplier has bubbled up ahead of this weekend’s United States Grand Prix.

A lawsuit has been lodged in a court in Texas, with the previous fuel flow supplier putting pressure on the incumbent as Formula 1 returns to the United States.

Formula 1 supplier faces patent lawsuit ahead of United States Grand Prix

A patent dispute has hit the Formula 1 paddock as teams arrive in Texas for this weekend’s United States Grand Prix at the Circuit of The Americas.

Sentronics Holdings Ltd., a British manufacturer of ultrasonic fuel flow sensors, served as the exclusive fuel flow meter supplier to the FIA between 2018 and ’25, but the governing body opened up the tender process for the supply in late 2023.

German manufacturer and market rival, Allengra GmbH, commenced the supply of fuel flow meters as a specification part for this season, with every car on the grid utilising a fuel flow meter supplied by the company.

However, Sentronic has opted to lodge a federal lawsuit in the U.S. District Court for the Western District of Texas, seeking damages and rulings against its successor as an F1 parts supplier.

What is the key dispute?

The lawsuit, a copy of which has been seen by PlanetF1.com, claims that Allengra’s fuel flow meters infringe upon Sentronics’ patent in the United States.

Sentronics’ ‘609 Patent’, which is U.S. Patent No. 11,391,609, is dated July 19, 2022, and indicates Andrew Cawte and Nathaniel Jones of Salisbury, UK, as the inventors of a fuel flow meter using a method of phase-modulated ultrasonic signals sent in opposite directions through a fluid path.

The patent was applied for in mid-2017, before being issued by the US Patents Office five years later.

In that same month in 2022, Allengra announced its first-generation F1 fuel flow meter prototype, calling upon its almost two decades of experience as a manufacturer of ultrasonic flow sensors.

Following both companies applying for the 2026-2030 fuel flow meter tender announced by the FIA in November 2023, Allengra won the contract in November 2024, replacing Sentronics.

However, Sentronics alleges that its technology patent covering its methodology is also in use in Allengra’s meters, which is said to be using the same phase-modulation technology protected under Sentronics’ ‘609 Patent’.

According to Sentronics, its own lab testing in late 2024 confirmed that Allengra devices are using the same patented methodologies.

In its complaint, Sentronics alleges it shared proprietary technical details with the FIA, under the usual non-disclosure rules for such agreements.

“Sentronics Holdings Limited (“Sentronics”), files this Complaint for infringement of its United States Patent No. 11,391,609 (“the ‘609 Patent”) in violation of Sections 271(a), (b), and (c) of Title  35 of the United States Code, by Allengra GmbH (“Allengra”),” began the complaint, “through its making, using, selling, offering for sale, or importing ultrasonic fuel flow measurement devices into the United States, and by inducing others, including Formula 1 (“F1”) racing teams and the Fédération Internationale de l’Automobile (“FIA”), to use such devices in the United States, including at the United States Grand Prix in Austin, Texas, the Miami Grand Prix in Miami, Florida, and the Las Vegas Grand Prix in Las Vegas, Nevada.

“Upon information and belief, Allengra’s fuel flow sensors, including without limitation, Allengra’s FIA Fuel Flow Meter and all Allengra fuel flow meter products of substantially the same design, including variants marketed for WEC, IMSA, WSBK and other motorsport applications (collectively, the “Accused Products”), practice one or more claims of the ‘609 Patent.

“By supplying the Accused Products for use in F1 and other motorsport series that compete in the United States, and by actively marketing the Accused Products to United States customers in motorsport, UAV, aviation, marine, general automotive, and other industries, Allengra infringes and has infringed the ‘609 Patent, and has induced and contributed to infringement by racing teams and others operating in the United States.

“Allengra has been on notice of the ‘609 Patent and the patent family to which it belongs since at least August 2025, when Sentronics served formal written notice of infringement of the European counterpart patent, EP 3 449 221 B1. Allengra’s continued infringement of the ‘609 Patent in the United States is therefore willful.”

Sentronics, therefore, is arguing that importing and using these parts in a race in the United States constitutes direct patent infringement.

Sentronics’ U.S. lawyers also sent a formal demand letter in April 2026. According to the filing, Allengra’s U.S. counsel disputed the claims but did not offer a technical non-infringement defence, and Allengra continued its operations.

The lawsuit has highlighted that F1 contracts carry significant marketing value beyond direct revenue.

Suppliers use an F1 pedigree to market products to automotive, aviation, marine, and UAV industries. Sentronics claims that Allengra is improperly using stolen technology to win contracts and build relationships in commercial markets that Sentronics has spent years developing.

Could this case have an effect on the United States Grand Prix?

For now, the filing of this lawsuit will have no immediate effect on the United States Grand Prix at the Circuit of the Americas, unless the court takes the immediate, and extraordinary, step of issuing an emergency temporary restraining order (TRO) – an order that is not being sought at this point.

Sentronics has requested, via a permanent injunction, that the court, “permanently enjoin Allengra GmbH, its affiliated entities including Allengra SRL, and their respective officers, directors, agents, servants, employees, attorneys, and all persons in active concert or participation with them, from further infringing the ‘609 Patent, including from making, using, selling, offering to sell, importing, supplying, or supporting the Accused Products or practicing, or inducing others to practice, the claimed methods of the ‘609 Patent within or directed to the United States.”

This means that, at present, the race weekend will proceed as planned with Allengra’s mandated sensors onboard the F1 cars.

As discovery progresses in federal court, Allengra could be forced to lay bare its proprietary firmware, source code, and design documentation.

As for the FIA, the governing body acknowledged receipt of Sentronics’ notification of the potential patent dispute “on September 17, 2025, through a communication from Najima Yattochane on behalf of FIA Single-Seater Director Nikolas Tombazis, confirming that the contents of the communication were ‘duly noted’.”

The outcome of the lawsuit could heavily impact future seasons or force a settlement between the two companies, with Sentronics seeking financial compensation for lost profits and royalties dating back to the patent’s issuance in mid-2022.

With Sentronics calling upon a trial by jury, it is also seeking a judgment that Allengra has directly and wilfully infringed the ‘609’ Patent, and is seeking up to three times the actual damages awarded due to this wilfulness.