Sentronics sues F1 fuel meter supplier Allengra ahead of the US Grand Prix

Sentronics Holdings Ltd, Formula 1’s fuel flow meter supplier until 2025, has sued its replacement, Allengra GmbH, alleging that the sensors fitted to every car in the championship infringe a US patent. The case was filed in a Texas federal court just days before the United States Grand Prix, but Sentronics has not asked for an emergency order that would prevent the meters being used this weekend.

The British company filed its complaint in the US District Court for the Western District of Texas on 16 October. It is seeking a jury trial, according to the court docket.

Fuel flow meters monitor how much fuel reaches each engine, allowing the FIA to enforce technical limits. The readings matter because fuel flow affects the power produced by an engine’s internal combustion unit. The technology is also among the regulation changes discussed in our guide to F1’s 2026 fuel flow meter.

Sentronics says the meters use its patented method

Sentronics says it held the FIA’s exclusive supply contract from 2018 to 2025. Allengra won the contract for 2026 to 2030 in November 2024, and Sentronics now claims that the German manufacturer’s meters infringe US patent 11,391,609, granted to Sentronics in July 2022.

The patent concerns measuring vehicle fuel flow with ultrasound. In general terms, the method compares signals travelling through a fluid in opposite directions: their travel times differ depending on whether they move with or against the flow. Sentronics says its approach sends paired signals in both directions and adjusts their phase to determine the flow rate.

The complaint alleges that Sentronics’ laboratory tests in late 2024 confirmed infringement. It also says the company had shared technical information with the FIA under a non-disclosure agreement. Sentronics accuses Allengra of direct infringement and of encouraging the FIA and teams to use the meters in the United States, including at Austin, Miami and Las Vegas.

No emergency request to halt use at Austin

Sentronics alleges the infringement was deliberate. It says Allengra was notified of the European patent in August 2025, while a demand letter sent in April 2026 was disputed by Allengra’s US counsel. The complaint also says the FIA acknowledged Sentronics’ earlier notice on 17 September 2025.

The former supplier is asking the court to permanently bar Allengra from making, selling or supplying the meters in the US. It is also seeking lost-profit and royalty damages dating back as far as 2022, and asks for those damages to be tripled on the grounds that the alleged infringement was wilful.

However, Sentronics has not sought an emergency ban on use of the parts. The case therefore does not, on the complaint’s current terms, call for the meters to be removed from cars at the United States GP. The lawsuit lands amid a busy Austin weekend, with several storylines shaping the event.