Nico Rosberg believes this weekend's British Grand Prix will be more dangerous than last year - despite new rules designed to slow down Formula One cars.

All teams, except Scuderia Toro Rosso, were forced to adopt smaller engines this year after world governing body the FIA acted to cut speeds.

That move has trimmed top speed but the new engines rev higher than their predecessors, allowing drivers to corner faster than before, aided by softer tyres this season.

That increase in cornering speeds will be particularly apparent at Silverstone, a track famed for its long, fast corners which Rosberg expects drivers to negotiate faster than ever.

The Williams driver said: "Copse is 30mph quicker than it used to be. It's flat now and you used to brake.

"The new engines were brought in to slow the cars down but it has not worked.

"It has worked partially but the danger is mainly on the corners obviously and there we are going quicker so that is not a good thing."

Rosberg's fears are shared by team-mate Mark Webber and former Williams driver Juan Pablo Montoya, who are both worried that tyre barriers are too close at Silverstone too cope with increased speeds.

But rookie Rosberg admits he has not raised those fears with his peers, claiming little can be achieved before this weekend's race.

He added: "I haven't talked to the other drivers because it's a bit of a waste of energy.

"In the short term nothing can happen anyway and in the long term the influence the drivers have is so small I would rather concentrate on other things and go flat out.

"You always want more run-off. We need to slow the car down full stop, not make the run-off wider."

World champion Fernando Alonso revealed British fans will enjoy the rare spectacle of a 200mph-plus Formula One car at full throttle for almost half a lap.

With tyre changes back for 2006, drivers are able to use softer, grippier' rubber which enables them to corner faster and, with less powerful engines, they have less need to back off.

Alonso believes that makes for a harder time for drivers but he is relishing a "fun" new challenge.

The Renault driver said: "The circuit is certainly very different now with the engines, to how it was last year.

"We have a lot of high-speed corners at Silverstone, and even though this year's cars have less power, there is more grip thanks to the softer tyres.

"That means we are much quicker in the corners, and a lot of the first part of the lap is now nearly flat out.

"It makes the circuit tougher physically - with so many high-speed corners, and quite a bumpy track surface, Silverstone is difficult for the drivers to cope with.

"Then, of course, it is a question of fun. It is always a nice feeling to be attacking high-speed corners and be right on the limit."