About F1

Scrutineering and technical checks

Scrutineering is the process of checking that each car meets the technical regulations. The FIA's technical delegate and their team inspect the cars through the weekend, and any car that breaks the rules is reported to the stewards. A car found to be illegal after a race is normally disqualified.

Before the weekend

Before any running, teams have to present their cars for checks and declare that they comply with the regulations. Scrutineers look at things like:

  • the dimensions of the bodywork
  • the survival cell and safety equipment
  • the driver's ability to get out of the car quickly
  • that sealed parts, such as power unit components, haven't been tampered with

New chassis must already have passed the FIA's crash tests before they get this far.

During the weekend

Scrutineering carries on all weekend. The FIA can check any car at any time, and it does several routine checks:

  • The weighbridge. In practice and qualifying, cars can be called into the FIA garage at random to be weighed. Drivers who are selected have to stop at the weighbridge on their way back to the pits.
  • Load tests. Wings and floors are pushed with set loads to check they don't bend more than the rules allow. Teams are always tempted to make bodywork that flexes at high speed to reduce drag, and these tests keep that in check.
  • Software and data. The FIA sees the data from every car's standard control unit, which lets it check things like energy use and fuel flow in real time.

After qualifying the cars go into parc fermé, which limits what teams can change before the race.

After the race

The most detailed checks happen after the race. Every car that finished is weighed, and the FIA picks some cars for a closer look, including taking parts apart. Two checks catch people out more than any others:

  • Plank wear. A plank runs along the underside of every car. It stops teams running the car too close to the ground, because if it wears down beyond the permitted limit, the car is disqualified. Lewis Hamilton and Charles Leclerc were both disqualified from the 2023 United States Grand Prix this way, and Hamilton again at the 2025 Chinese Grand Prix.
  • Fuel. Every car must have enough fuel left for the FIA to take a sample, and that sample must match the fuel the supplier registered. See fuel.

Not every car is stripped down after every race. The FIA checks a selection, chosen to cover a range of teams, so a car that wasn't picked might have passed or failed a check it never had.

Technical directives

The regulations can't predict every clever idea. When the FIA wants to explain how it will interpret a rule, or close a loophole, it sends teams a technical directive. These aren't new rules, but teams follow them, because a car that ignores one is likely to be reported to the stewards.

When a team thinks a rival is illegal

Teams watch each other closely. If one believes another's car is illegal, it can ask the FIA to look at it, or lodge a formal protest with the stewards. See protests, appeals and the right of review.