The FIA has issued a technical directive to clamp down on Formula 1 teams exploiting a loophole in the rules over preventing plank wear.
Autosport understands the technical directive removes some freedoms provided by an earlier directive to help preserve the plank by installing supporting skid blocks on the floor.
Under the current ground-effect regulations teams have been trying to run their cars as low as possible to the ground to extract maximum downforce, while trying to stay within the 1mm allowance of wear from the floor plank.
To help prevent wear around the four holes the FIA measures, teams are allowed to install metal skid blocks around areas where they expect the most wear.
A previous technical directive gave teams further scope to add supportive skids, also known as satellite skids, on the plank further away from the four measuring points.
Those support skids were understood to be legal as long as they had the same vertical stiffness as the main skids, but they didn't reference thickness.
In recent weeks some teams, including Ferrari but not Red Bull's other rival McLaren, were deemed to have taken advantage of the provision to go beyond what is intended and come up with thicker protections that help protect the main skids.
Autosport understands Red Bull flagged the issue with the FIA after the Brazilian Grand Prix.
The FIA accepted Red Bull's argument that Ferrari and some other teams are exploiting a loophole in the rules. Rather than wait until Qatar to give teams more time to react, it therefore issued a technical directive that is active with immediate effect, starting from this weekend's Las Vegas Grand Prix.
The directive effectively takes out the reference allowing these additional protective skids, which means teams will likely have to take extra margin with their ride heights to reduce the risk of exceeding the 1mm of plank wear allowance.
That last led to the disqualification of Mercedes' Lewis Hamilton and Ferrari driver Charles Leclerc at last year's United States Grand Prix.
Having to raise the front and ride heights of the car by 1mm is believed to be worth anywhere from half a tenth to a quarter of a tenth, which could make a difference on 2024's tight grid as McLaren, Ferrari and Red Bull fight it out at the front.
