Perez admits tyre concerns

McLaren's Sergio Perez is worried the latest range of Pirelli tyres could turn this year's grands prix into pit stop free-for-alls.

Perez finished the second day of the second pre-season Formula One test at Barcelona's Circuit de Catalunya on Wednesday at the top of the timesheet.

Perez's time was two-tenths of a second faster than the best from the eight days of testing at the track last pre-season as Pirelli appears to have delivered on its vow to make this year's rubber quicker.

As a further part of the revolution, Pirelli also believes each driver will face at least two pit stops per race this year.

Perez, however, fears Pirelli may have gone too far as he said: "It's extreme. The degradation is very difficult. It's a big surprise.

"Normally in winter testing we see a lot of degradation, but never this much.

"We are going to have a race here (Spanish Grand Prix in May) so it's a bit of a worry.

"But we are still learning about the tyres and I think once we go racing I hope things will change.

"I hope it changes, because if we are in this situation in Melbourne (venue for the season-opening race on March 17) we are going to see something like seven or 10 stops."

Lewis Hamilton has also admitted looking after the tyres "isn't easy" after a day in which he racked up 121 laps in his Mercedes yesterday.

Force India's Paul Di Resta, though, believes he and his team are beginning to develop a strong understanding of the new Pirellis.

"Understanding the tyres is always a priority and we're getting a feel for the degradation rates, which have been quite high," said Di Resta.

"However, we have to remember the track temperatures here are lower than we can expect at most races.

"Learning about the tyres and a new car at the same time is never easy, but we're pretty pleased with how things have gone during the first couple of days."