A full investigation of Oscar Piastri's Miami-winning car has ruled out talk of it being illegal.

Other than the ongoing concern about flexing, doubts have been raised in terms of how the Woking team is able to suffer less tyre deg than its rivals, which has led to claims that water is being used to the brake assembly and tyres in contravention of Article 11.5 of the technical regulations.

However, post-race investigation of Piastri's Miami MCL39 has ruled out any chicanery.

"After the race in Miami car number 81 was randomly chosen among the top ten cars for more extensive physical inspections," the FIA's technical delegate, Jo Bauer confirmed today. "Subject to these physical inspections were the wheel bodywork assemblies.

"The following checks were carried out on all corners: The compliance of all components with TR Article 3.13. Physical checks for compliance with TR Article 11.5 on all four corners.

"All inspected components were found to be in conformance with the 2025 Formula One Technical Regulations."

Charles Leclerc's Ferrari was also checked, with the physical steering wheel assembly cross checked against the OSC submission as per TR Article 17.6. The clutch operating device was examined and checked against TR Article 9.3.2. and the electronic submission, which was supplied by the team as part of TD001, was checked against the physical steering wheel.

General compliance checks were carried out against TR Articles 8.3 and 8.7 and, like McLaren, all inspected components were found to be in conformance with the 2025 Formula One Technical regulations.

Speaking in Miami, Christian Horner admitted that when as car is dominant there will always be suspicion as to its legality.

"I'm not suggesting that there's anything illegal on the car," he said. "Well done to McLaren, they were in a league of their own.

"Of course in Formula 1 there are always going to be questions that are raised," he added, his team having just failed to successfully protest George Russell's podium finish for a yellow flag infringement. "They (McLaren) did exactly the same about the front suspension on our car last year. So it's inevitable when you're running at the front, as we have for the last few years, you always come under more scrutiny.

"McLaren have got the car to beat at the moment, that's quite clear," he admitted. "They're going to be tough to beat over the next few races."