Formula 1 has changed its fuel temperature rules and deflection test requirements as part of a series of changes to sporting and technical regulations approved by the FIA World Motor Sport Council.
The fuel-related change follows Aston Martin having to start the Miami Grand Prix from the pits due to its fuel being too hot and suspicions from rivals that Red Bull had fuel temperature issues ahead of the Grand Prix from Spain. .
Previously, the rule simply stated that the fuel intended for use in the car could not be more than 10°C lower than the ambient temperature.
Now that article 6.4.2 of the technical regulations has been revised, this means that in races where the ambient temperature is above 30°C, it will be permitted to have the fuel at 20°C – while ensuring that the fuel can still only be 10°C below ambient temperature on colder runs.
The regulations now state that this will be measured by each car’s main fuel flow meter.
Changes have also been made to the rear wing and beam wing deflection tests amid concerns over body flexibility.
The trailing edge of the rear wing is now allowed to deflect up to 3mm along the load application line, whereas previously it was only allowed 2mm deflection. The load used in this test remains unchanged at 200N.
The change to the beam wing flexibility test is more substantial. Originally, this regulation (article 3.15.12) did not allow more than 5 mm of deflection under a load of 60 N.
The allowable deflection has now been changed to mean that no part of the beam flange assembly “may deflect more than 3mm when a load of 150N is applied to its trailing edge, normally to the surface lower part of the element”. This load will be applied simultaneously in two places.
Markers should also be added to the rear wing to facilitate monitoring of its deflection by on-board cameras.
There is also a modified test for the DRS slot gap, with a spherical gauge with a diameter of 85 mm not allowed to pass between the two elements.
Another change that has been made to the technical regulations concerns the rule on so-called “unsafe construction”.
Previously, this stipulated that “the stewards may exclude a vehicle whose construction is deemed to be dangerous”.
But it is now amended to specify that “the marshals may prohibit the participation of a vehicle whose construction is deemed dangerous. If the relevant information appears during a session, such a decision may apply with immediate effect”.
Amid controversy over driver safety given the violent vertical oscillations of the cars, it underscores the ability of the marshals to take immediate action if they believe the car is not running within acceptable parameters.
It is likely that this is related to the intention to introduce a metric preventing drivers from being subjected to a certain intensity of such oscillations, which makes it adamant that a car could immediately be black flagged.
Parc Fermé rules have been changed, with power unit components being able to be changed to one of a newer specification.
There is also a new rule that allows teams to request routine repairs to powertrain components “in the form of a patch made of the same or composite material, following damage or failure”.
This will only be accepted if it is “local and minimal” and can only be done on a temporary basis.
Meanwhile, to improve visibility, the mirror regulations have been changed to improve the shape of the mirror surface.
The sporting regulations have also been changed to clarify car limits for tire testing following question marks earlier this year.
The media activity schedule has been rumored to be changed, with driver press conferences returning to Thursdays and now featuring 10 drivers.
Regulations governing the choice of starting tires have been clarified after confusion at the Monaco Grand Prix when race director Eduardo Freitas ordered all cars to use wet tires for the safety car start.
The rules now make this mandatory for both race starts and restarts after the red flag where more than one lap behind the safety car is required.
Finally, the WMSC was updated on the status of the 2026 Powertrain Regulations.
These will be finalized in the coming weeks and presented to the WMSC for ratification at its next meeting in September.