Characteristic of the new Pirelli tyres wear could make it difficult to anticipate in 2011, according to the boy wonder German Sebastian Vettel.
Red Bull Driver said that the new tyres this year left many 'marbles' rubber in the drawn.
"Half the distance (in races), there so many on the track that the adjustable rear spoiler will not help", said Vettel.
"Is because when you're out of line, you have to brake much earlier," he explained.
