Formula 1’s former fuel flow meter supplier, Sentronics Holdings Ltd, has taken its replacement to court in Texas. The company claims that the sensors now used by every car in the championship infringe its patent.
The British company filed the case against German manufacturer Allengra GmbH in the US District Court for the Western District of Texas on 16 October. This comes just days before the United States Grand Prix in Austin. According to the court docket, Sentronics has demanded a jury trial and filed two exhibits alongside its complaint.
What are fuel flow meters?
Fuel flow meters measure how much fuel reaches each engine, allowing the FIA to police the flow limits set out in the technical regulations. The FIA wants to keep an eye on this, because a change in fuel flow means a change in power produced by the internal combustion engine.
According to the complaint, as reported by PlanetF1, Sentronics was the FIA’s exclusive supplier from 2018 to 2025 before Allengra won the contract for 2026 to 2030 in November 2024. The two companies are now butting heads, as Sentronics claims Allengra’s meters infringe its US patent, 11,391,609, which was granted to Sentronics in July 2022.
The patent, titled "Flow meter", relates to "a method and an associated flow meter for measuring fuel flow rate in a vehicle". It explains that ultrasonic flow meters work on the principle 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' method sends pairs of signals in opposite directions and alters their phase to measure the flow.
What Sentronics is claiming
The complaint says Sentronics’ own laboratory testing in late 2024 confirmed the infringement. It also says Sentronics shared technical details with the FIA under a non-disclosure agreement.
As well as direct infringement, Sentronics accuses Allengra of encouraging the FIA and the teams to use the meters in the United States, including at the races in Austin, Miami and Las Vegas.
The complaint alleges the infringement was a deliberate choice, adding that Allengra was told about the European version of the patent in August 2025. Sentronics’ lawyers sent a demand letter in April 2026, which Allengra’s US counsel disputed.
According to the complaint, the FIA confirmed receiving Sentronics’ earlier notice on 17 September 2025, saying its contents were "duly noted".
Sentronics is now asking the court to permanently ban Allengra from making, selling or supplying the meters in the US. Unsurprisingly, it is also seeking damages for lost profits and royalties dating back to as far as 2022. In fact, it wants those damages tripled because it says the infringement was wilful.
Will the US Grand Prix be affected?
No, the race weekend won't be affected at all as Sentronics hasn't asked for an emergency ban that would stop the usage of these parts as Kimi Antonelli fights for his championship win. The court has been asked to issue a summons, which is a normal step for serving the case.