F1’s Former Fuel Flow Meter Supplier Sues Replacement Ahead of US GP

Sentronics Files Patent Infringement Lawsuit Against Allengra in Texas

A major legal dispute has surfaced in Formula 1 over the critical technology used to monitor engine performance. Former official fuel flow meter supplier Sentronics Holdings Ltd has taken German rival and current supplier Allengra GmbH to court, alleging that the ultrasonic sensors currently fitted to every car on the grid infringe its proprietary intellectual property.

The British company filed the lawsuit in the US District Court for the Western District of Texas on 16 October, just ahead of the United States Grand Prix at Circuit of the Americas in Austin. According to the court docket, Sentronics has requested a jury trial and submitted two technical exhibits alongside its complaint, alleging that Allengra’s devices violate US Patent 11,391,609, which was officially granted to Sentronics in July 2022.

The Technical and Commercial Dispute Behind F1 Fuel Flow Monitoring

Fuel flow meters play an indispensable role in contemporary Grand Prix racing. They measure the precise quantity of fuel reaching each internal combustion engine, enabling the FIA (Fédération Internationale de l’Automobile) to enforce strict regulatory limits. Because variations in fuel flow directly correlate with engine power output, robust and standardized monitoring is vital to maintaining technical parity and rule compliance across competitors.

According to the legal filing, Sentronics served as the FIA’s exclusive fuel flow meter supplier from 2018 to 2025. However, Allengra was awarded the exclusive contract covering 2026 to 2030 in November 2024. The lawsuit centers around the operational mechanics defined in Sentronics’ patent, titled Flow meter, which outlines a method and an associated flow meter for measuring fuel flow rate in a vehicle.

The patent specification explains the operational physics of ultrasonic measurement, noting that the propagation time of ultrasonic signals travelling through a fluid between two fixed points varies depending on whether the signal travels in the direction of flow or against the direction of flow, with signals propagating more quickly when travelling with the flow. Sentronics’ patented technique relies on sending pairs of signals in opposing directions and altering their phase to calculate dynamic flow rates. The plaintiff states that internal laboratory testing performed in late 2024 confirmed that Allengra’s hardware infringes on this exact methodology.

Allegations of Wilful Infringement and Commercial Relief

In its complaint, Sentronics outlines an extensive timeline of prior warnings. The British firm notes that it previously shared proprietary technical data with the FIA under a non-disclosure agreement. Sentronics further claims that Allengra was formally alerted to the European counterpart of the patent in August 2025. Following that notice, Sentronics’ legal team issued a formal demand letter in April 2026, which was subsequently disputed by Allengra’s US legal counsel.

The FIA was also informed of the dispute; according to court documents, the governing body confirmed receipt of an earlier notice from Sentronics on 17 September 2025, stating that the communication was duly noted.

Beyond claiming direct infringement, Sentronics accuses Allengra of inducing infringement by actively encouraging the FIA and participating Formula 1 teams to utilize the contested sensors at Grands Prix hosted in the United States, specifically mentioning rounds in Austin, Miami, and Las Vegas. Sentronics is petitioning the court for a permanent injunction prohibiting Allengra from manufacturing, marketing, or selling the units within the US. Additionally, Sentronics is pursuing damages for lost profits and reasonable royalties reaching back to 2022, requesting that the financial award be tripled on the grounds that Allengra’s infringement was deliberate and wilful.

Why This Matters

The supply of single-spec, FIA-mandated components represents both high financial stakes and significant technical prestige for motorsport engineering firms. Because fuel flow sensors dictate how the FIA polices power unit regulations, any intellectual property conflict surrounding these devices places regulatory bodies and participating teams in an uncomfortable spotlight. A potential US injunction against Allengra could create complex operational hurdles for the FIA’s technical delegate team during American race events if alternative compliance solutions or licensing agreements are not reached. For the immediate future, however, the court process remains in its preliminary phase with the issuance of a standard summons, ensuring that current racing events—such as Kimi Antonelli’s ongoing championship fight—continue without trackside disruption.

Frequently Asked Questions

Will the lawsuit impact the United States Grand Prix?

No. Sentronics has not filed for an emergency injunction or temporary restraining order to block the immediate use of Allengra’s fuel flow meters in Austin, meaning track sessions and technical scrutineering will proceed as scheduled.

What specific penalties is Sentronics seeking against Allengra?

Sentronics is requesting a permanent injunction barring Allengra from manufacturing, selling, or supplying the disputed meters in the United States, as well as lost profits and royalties dating back to 2022, with a request for those damages to be tripled due to alleged wilful infringement.

What role do fuel flow meters play in Formula 1?

Fuel flow meters measure the volume and rate of fuel moving from the tank into the internal combustion engine. The FIA relies on these standardized sensors to guarantee that no team exceeds the maximum fuel flow limits mandated by the sport’s technical regulations.