Teams not revealing flexible front wing secrets

Red Bull and Ferrari's rivals will need to move fast to design flexible front wings for their own cars.

That is the claim of Renault boss Eric Boullier, who believes F1's most competitive teams at present are enjoying a big benefit from the innovation.

Although flexible wings are illegal, the designs currently raced by Red Bull and Ferrari have passed scrutineering and the existing FIA tests.

"I hear rumours and I read the press," Boullier is quoted by Auto Hebdo. "I'm hearing (the wings are worth) about three tenths, which seems right."

But the first step for the teams' competitors will be understanding how the wings are flexing so much at speed while still passing the compliance tests.

"It doesn't just seem to be their wing that flexes," McLaren's Jenson Button said in Hungary. "We're not sure how they are doing it legally. It's worrying."

It is understood that the rival teams are putting pressure on the FIA for Red Bull and Ferrari to have to explain precisely how the wings are legal.

But Ferrari's Stefano Domenicali said: "If you pass the tests, you're done."

And Red Bull's Christian Horner added: "I take it as a compliment to our engineers when a fuss like this is made."