Following the revision of the test for wing flexibility two of the most outspoken critics of Red Bull (and Ferrari) claim that the new test has made a difference.

Following claims that the front wings on the Red Bull and Ferrari are flexing at high speed, the FIA introduced a revised test at Spa this weekend, which the Red Bull - and, ironically, the McLaren, duly passed.

However, despite Mark Webber taking pole for the Belgian GP, Martin Whitmarsh and Ross Brawn both believe that the revised test has made a difference.

"I wasn't that confident that it would be nailed," Whitmarsh told reporters when asked about the problem perceived flexing, "but I have to say, the wings were of a different stiffness and positional domain than they had been in previous races.

"I think we could all see it," he continued, "and the evidence that was collected yesterday showed that in regards to stiffness and position the front wing endplates of those cars appear to be in a different domain."

"I think all of us can see that what was visible in the last couple of races doesn't seem to be the case here," said Brawn in a separate press conference. "I don't know what has happened but it looks visually to me to be different."

However, Christian Horner continued to play down his rivals suspicions, telling reporters that the wings used this weekend are the same as those used in Hungary.

"We've been questioned so many times this year, whether it be ride-height systems, whether it be suspension, whether it be blown diffusers," he said. "It has been the front wing and now it is the floors, so our guys take it as a compliment that so much of the car has attracted so much attention."

The flexing test will be tweaked once again in time for the race at Monza.