Drivers 'need time' with wing

The Mercedes driver said he had been taken by surprise by some of the system's characteristics when he tested it on the new W02 at Valencia this morning.

"That takes some getting used to because you push the button, you feel a little bit that the car gets lighter, then you release the button before braking and think 'Jeez, what if this thing hasn't gone back to its old position?' Then you're off in a big way," said Rosberg.

"It takes some adjustment. That's going to take some time. It's not that different to the KERS, but still the rear wing moves and you don't really know how quick it gets back into its normal working area once you release the button again.

"With the KERS we could release very late before the braking, so now that feels a natural way of doing it. Now you don't know if it's going to be properly attached... That's a bit of a concern."

The German is confident that if the new wing improves the racing, no one will be too concerned about its technicalities.

"I think the idea behind it is good, because it definitely should make overtaking easier, and in the end, nobody is going to ask why overtaking was easier," said Rosberg. "If the racing is more exciting and more spectacular then that's it, full stop - F1 has become more exciting.

"So I think the idea is good, but it's not simple. For sure you still need to think about it a little bit - if it really is the right thing to do. Because there's a lot going on now, with the rear wing, with KERS and this and that. KERS is also something that you need to hold for a specific amount of time, so you need to think about that too.

"All of it takes a lot of getting used to, for sure. It doesn't come naturally to start off with. When you've got the hang of it, you need to judge - does it distract you too much when you're in a race situation with all those things going on? We need to keep an open mind on that. But the FIA has said anyway that they will keep an open mind."

Asked by reporters if he was concerned that it might make grands prix more like Formula Ford races, Rosberg replied: "Isn't that what you'd like to see? I think for sure things could get a lot more interesting, especially in the first laps when everyone is within a second anyway. It's going to be all over the place, maybe.

"But that would only be good, I guess. It's also with KERS - how much do you use at the start? All of that. Then you have none left for the back straight. You have a lot of new challenges."