The FIA has been working to stop teams from using flexible rear wings to gain an advantage. Over the last year, some teams found ways to slightly bend their wings while still passing the official tests. This helped them reduce drag and go faster on straights, like a small version of the DRS system, a trick known as the “mini-DRS” effect. To stop this, the FIA brought in new rules for 2025 to make the wings stiffer and harder to flex.

At the start of the season, the limit for how much the rear wing could bend under pressure was set at 2mm. But after the race in Australia, the FIA noticed that some teams were still able to flex their wings more than expected. So, for the Chinese Grand Prix, they introduced even stricter rules under which the rear wing can only flex 0.5mm, with a small extra allowance of 0.25mm just for this race.

Some teams had to change their wings to meet the new limits. Alpine openly admitted  it made changes before China, while Haas said it was close to the limit but didn’t need to adjust anything.

Other top teams didn’t say much, but the FIA’s technical boss, Nikolas Tombazis, confirmed (via Motorsport-Total.com) that “four or five teams weren’t [compliant], and they had to make changes [for China].” He added: “I’m hopeful it’ll be enough this time.”

The FIA checks wing flexibility using both load-bearing tests (where they press down on the wing with weight) and cameras that monitor the cars while they’re on track.

“We continue to use cameras, simply to be safe,” Tombazis explained. He also said that if they see something strange on the cameras, they might investigate further to make sure there’s no hidden mechanism or clever trick behind it.

He finished by saying the FIA is “reasonably satisfied at the moment,” but they’ll keep watching closely. “The teams are obviously still trying to get the most out of their cars, and we have to remain vigilant,” he said. And while a car that passes the test is usually seen as legal, the FIA still has the right to do extra checks if they suspect anything unusual.