Sebastian Vettel has expressed concern about the increasing focus on F1’s "show" factor.

The reigning world champion was referring to the adjustable rear wing innovation for 2011, as well as new supplier Pirelli’s intention to increase the need for pitstops by supplying less durable tyres.

"F1 is becoming more radical, with more and more attention being put into the show. I wonder if this is necessary," he told the German magazine Der Spiegel.

Fernando Alonso infamously declared a few years ago that F1 is "not a sport".

"It is too much a business to be a sport, and too much a sport to be a business," he now clarifies in AS newspaper.

"But it is not just a sport purely and simply, because there are too many interests and too much at stake," added the Spaniard.

There have been rumblings within the paddock that, with KERS also returning in 2011, the demands on the drivers are becoming unreasonable.

"If a critical point is reached," German Vettel said, "we would sit down together and discuss it. It’s about our safety."

One of the safety concerns is an apparent delay between the pressing of the button and the time it takes for the adjustable rear wing to click back into place before braking.

At Jerez last week, observers said there were several drivers having problems under heavy braking after the long straight.

"There is a sort of ’no man’s land’ of at least 5 metres when the load on the wing is not felt yet," Jarno Trulli confirmed.

But McLaren’s Jenson Button countered: "Actually I was quite surprised how quickly it (the wing) reacts to the pressing of a button."