Sentronics Holdings sues Allengra GmbH over fuel flow meter patent
Sentronics Holdings filed a patent infringement lawsuit against Allengra GmbH in Texas, alleging the unauthorized use of ultrasonic fuel flow meter technology. The dispute involves FIA championship components and seeks damages for lost profits and royalties dating back to 2022.
Legal action in the Western District
Sentronics Holdings Ltd filed a patent infringement lawsuit against Allengra GmbH in the US District Court for the Western District of Texas on 16 October. This filing comes just days before the United States Grand Prix begins in Austin. Sentronics claims the fuel flow meters used by every car in the championship infringe its US patent, 11,391,609. This patent, titled "Flow meter", was granted in July 2022 to inventors Andrew Cawte and Nathaniel Jones of Salisbury, UK. The technology uses ultrasonic signals sent in opposite directions through a fluid path to measure the specific flow rate of fuel in a vehicle. The method relies on the principle that the propagation time of ultrasonic signals varies depending on whether the signal travels in the direction of flow or against it. I view the timing of this lawsuit as a direct response to the current racing schedule in the United States.
| Patent Detail | Information |
|---|---|
| Patent Number | 11,391,609 |
| Title | Flow meter |
| Grant Date | July 2022 |
| Inventors | Andrew Cawte and Nathaniel Jones |
| Technology | Phase-modulated ultrasonic signals |
Dispute over technology and contracts
Sentronics served as the FIA’s exclusive supplier from 2018 to 2025. Allengra won the contract for the 2026 to 2030 period in November 2024 and began supplying all cars on the grid this season. Sentronics claims its own laboratory testing in late 2024 confirmed Allengra devices use the same patented methodology. According to the complaint, Allengra was notified about the European version of the patent, EP 3 449 221 B1, in August 2025. Sentronics’ lawyers sent a formal demand letter in April 2026, which Allengra’s US counsel disputed, but the German manufacturer did not offer a technical non-infringement defence and continued its operations.
Allengra induced the FIA and racing teams to use the meters in the United States at races in Austin, Miami, and Las Vegas, according to the complaint. Sentronics also claims that Allengra uses this technology to win contracts in commercial markets like the UAV, aviation, marine, and general automotive industries. This behavior allows Allengra to build relationships in sectors that Sentronics spent years developing. Najima Yattochane, representing FIA Single-Seater Director Nikolas Tombazis, confirmed that the FIA received the notice on 17 September 2025. Sentronics also stated that it shared proprietary technical details with the FIA under a non-disclosure agreement. This dispute follows the FIA opening the tender process for the supply in late 2023.
The lawsuit alleges infringement in violation of Sections 271(a), (b), and (c) of Title 35 of the United States Code. Sentronics claims Allengra’s products, which include the FIA Fuel Flow Meter and variants marketed for WEC, IMSA, and WSBK, practice one or more claims of the patent. The company argues that Allengra’s continued use of the technology despite notice of the patent family makes the infringement willful. Allengra’s response was insufficient, as its US counsel disputed the claims but did not offer a technical non-infringement defence.
Impact on the US Grand Prix
The United States Grand Prix will proceed without any disruption because Sentronics did not request an emergency temporary restraining order to stop the usage of these specific parts for the cars. Kimi Antonelli continues his championship fight with the current sensors installed on the cars. Sentronics asks the court for a permanent injunction to prevent Allengra GmbH, Allengra SRL, and their respective officers, directors, and employees from making, using, selling, or supplying the Accused Products in the United States. These products include the FIA Fuel Flow Meter and all variants marketed for WEC, IMSA, and WSBK. Sentronics seeks damages for lost profits and royalties dating back to 2022. Because Sentronics claims the infringement was willful, it wants the court to triple the actual damages awarded.
