Red Bull not using F-duct in Hungary
Team boss Christian Horner confirmed the news to Germany's Auto Motor und Sport.
"The reason is simple," he said. "The wing without the F-duct is more efficient (in Hungary)."
The report also said Ferrari is not convinced the F-duct is the best solution for the tight and twisty layout, experimenting with one car not running the downforce-stalling device in morning practice.
Williams' Rubens Barrichello was surprised when he learned that some teams are not convinced about the F-duct at the Hungaroring.
"For sure we are starting with the F-duct. After that, we'll see," he said.
Another talking point in Hungary is the flexible front wings photographed on the Red Bull and Ferrari cars last weekend at Hockenheim.
"I am not saying they are doing something illegal," McLaren team boss Martin Whitmarsh is quoted as saying.
"But the fact is that the endplates are touching the ground," he said, apparently after seeing the slow-motion video captured by FOM of the Red Bull cars in morning practice.
"On the Red Bull, these end plates are even protected with a shield. We can't imagine how it's getting that low," added Whitmarsh.