FIA tweaks F1 rear wing deflection test for China

The FIA is imposing stricter load deflection tests for Formula 1 rear wings at this weekend’s Chinese Grand Prix after analysing Melbourne footage.

As part of a clampdown on teams exploiting aerodynamic elasticity to an undesirable degree, the FIA told teams over the off-season that it would impose stricter loads tests for both the front and rear wings.

The front wing clampdown will be introduced from the Spanish Grand Prix onwards at the end of May, while the stricter rear wing tests were already in use from the start of the season at last weekend’s Australian Grand Prix.

Having further studied the findings from the Melbourne weekend, the FIA has decided to tighten up the rear wing rules for China as it felt teams could still exploit wing flexing more than intended. It will be reducing the maximum slot gap width between the mainplane and the rear wing flap from 2mm to 0.5mm, when subjected to 75kg of vertical load.

“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,” the governing body said in a statement.

“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 FIA said all teams were informed on Monday morning of the decision to revise its technical directive, and stressed that all cars were found to be legal over the Australian GP weekend.