FIA tweaks F1 rear wing deflection test for China

Just a day after the season-opening Australian Grand Prix, the sport's governing body, the FIA has confirmed that a new technical directive will be introduced in time for this weekend’s Chinese Grand Prix in Shanghai.

The FIA had announced earlier this year that it would enforce stricter load tests for the front and rear wings in 2025. The more stringent deflection test for the rear wing came into force at Melbourne while the new load test for the front wings is set to be introduced in time for the Spanish Grand Prix which gives teams time to carry out the necessary tweaks to their front wing design.

However, the FIA, unexpectedly, announced a day after the Australian Grand Prix that a new technical directive will be introduced at this weekend's race in Shanghai.

Although the FIA noted that all cars were found to comply with the deflection limits in Australia, the Paris-based governing body noted that it has found ‘sufficient grounds’ for a ‘tougher test’ to be introduced at Shanghai with a focus on the upper rear wing.

The change dictates that the rear wing’s slot gap ‘must not vary’ by more than 0.5 millimetres when 75 kilograms of vertical load is applied to the rear wing mainplane, down from a range of 2mm stated in the F1 2025 regulations, with a tolerance of 0.25mm.

An FIA statement read: “As has been previously communicated, between the end of the 2024 season and the start of the 2025 season, the FIA exercised the authority it is granted under Article 3.15.1 of the Technical Regulations to introduce either new or more challenging load-deflection tests for the front wing (from Race 9, Spanish Grand Prix), the upper rear wing, and the beam rear wing.

“In addition, the FIA requested to the teams to use cameras in Free Practice Sessions to monitor the on-track deformations exhibited by the cars during the Australian Grand Prix.

“Having analysed footage from the rear wing deformations combined to the static deflections measured inside the FIA garage in Melbourne, the FIA has concluded that sufficient grounds exist for a tougher test to be introduced from the forthcoming Chinese Grand Prix on the upper rear wing.

“More specifically, Article 3.15.17, introduced in 2025, states that if 75Kg of vertical load is applied on either extremity of the rear wing mainplane, the distance between the mainplane and the flap (also known as “slot gap”) must not vary by more than 2mm.

“From the forthcoming Grand Prix in Shanghai, this limit will be reduced to 0.5mm. Due to the short notice for Shanghai only a tolerance of 0.25mm will be added to this new limit.

“The Teams were informed of this revised test early Monday 17th of March. The FIA wishes to further confirm that during the Melbourne event all cars tested against the requirements of Article 3.15.17 and found to comply, therefore all cars raced in Melbourne were deemed to be legal," noted the FIA.