Pirelli has exceeded expectations on its return to Formula 1 after 19 years away, according to many of the leading drivers who sampled the Italian company's rubber for the first time in Abu Dhabi.
All 12 teams ran at Yas Marina today, the first time that Pirelli tires have run on any car other that the Toyota TF109 test mule. With teams focusing on understanding the characteristics of the tires and how they will change the aerodynamic and suspension requirements of their 2011 cars, most drivers were positive with their feedback.
"Given the short amount of time Pirelli had, I think they did a good job," said World Champion Sebastian Vettel, who set the second-fastest time of the day. "It's a good start and it was good to be back in the car.
"You need to give the car a bit of time to adapt to the tires. We need to work on the setup, but I think it's a common view that the tires have behaved pretty well and probably better than a lot of people expected."
Rubens Barrichello, the only driver running today who has experience of racing in F1 on Bridgestone, Michelin and Goodyear rubber, was also impressed. He added that there is still much to learn about the characteristics of the tires.
"I've been positively impressed," said Barrichello. "The track is a little bit different because I think they polished the asphalt because of the Bridgestone rubber.
"I don't think it's time to make comparisons, but I thought it was positive. I did 42 laps in the morning and it was OK. They are different than Bridgestones and we need to keep learning. We could not expect a completely different tire to work the same way. I quite like the challenge."
Barrichello estimated the lap time performance to be "a couple of tenths" between the Bridgestones and the Pirellis, although Mercedes driver Nico Rosberg put the gap at 1.5-2sec. Paddock estimates suggest that the deficit is closer to two seconds – although a direct comparison of times is impossible owing to the changing track conditions.
Despite this, and his concerns that the tires will not help Mercedes overcome the front grip problems that it struggled with this year, Rosberg believes that the degradation of the tires will lead to dramatic races.
"It's quite heavy," Rosberg said when asked about the degradation of the tires. "If that's what they want and it's the same for everybody, then OK. Tires like that always give more exciting racing, so it's not necessarily a bad thing."
Pacesetter Felipe Massa also complained of the degradation, and suspects that changes will be made to the compound before Pirelli finalizes its tires for next year. He added that the performance of the soft tire possibly surpassed that of the Bridgestone super soft, which was allocated as the option tire for last weekend's Abu Dhabi Grand Prix.
"The harder compound has a lot of degradation and it's not as quick as I expected," Massa said. "As for the softer tire, I was very happy with it. It's quick, degradation is very good. I did long runs with both and the one I did with the softer tire was very good, possibly better than what I had last Sunday in the race.
"Of course, again, they'll have to work to improve the harder compound they brought here, but that's what this test was all about. Pirelli saw what happened, listened to our suggestions and understood the situation."
Renault's Robert Kubica, whose day was cut short by a mechanical problem and whose team then chose to save tires to maximize running tomorrow when the track is at its best, warned that judgment should be reserved. Comparisons with last weekend's race are made difficult by the amount of extra rubber laid down during the two-day driver test.
"It's difficult to compare, because we had a race five days ago and the track has changed quite a lot due to the testing and the rubber that was laid down," said Kubica. "I'm sure that the track grip is much better than it was in the race. "There's no point really in comparing them. There's quite a big difference. It is always pretty interesting when you change tires to feel the difference and make some setup changes and stuff like this.
"It's just to get an idea for next year's car which characteristics will work best. We will never get track conditions with so much rubber on the race weekends, so actually I don't think it's so significant, this test. A lot of the young drivers had many sets of new tires! Although the track was washed yesterday, I didn't recognize it. It was like a different track."
Tire testing will continue for a second and final day tomorrow, with Michael Schumacher (Mercedes), Fernando Alonso (Ferrari) and Mark Webber (Red Bull) the highest-profile drivers to try Pirelli's development rubber for the first time.