Pirelli Motorsport has been busy analysing the results of two weeks of pre-season testing. The tyre manufacturer is keen to confirm the effect the different compounds are having on the performance of the 2018 cars.
Pirelli's sporting director Mario Isola said that the test had given them a definite sense about the gaps - or delta - between each tyre.
“We now have a good idea of the performance differences between the compounds at this point of the season,” he said. Pirelli has introduced a new hypersoft tyre to the range available to teams this year.
“There is around 0.7 seconds between the ultrasoft and the hypersoft, which corresponds to our expectations," Isola reported.
"After an uncertain start with bad weather last week, pre-season testing eventually turned out to be very productive with more representative conditions this week," he said. "Just as we expected."
Even the inclement conditions had provided useful data. "It enabled the teams to also assess the wet-weather tyres and crossover points," said Isola.
Isola said that Pirelli's assessment of the comparative performances of the tyres was derived from "an average made from different teams" and by benchmarking the hypersoft against post-season testing in Abu Dhabi.
The hypersoft compound enabled Sebastian Vettel to set a new albeit unofficial track record on Thursday. His time of 1:17.182s is the fastest lap ever recorded at the Circuit de Barcelona-Catalunya.
With the exception of the medium tyre, all the compounds have been reformulated for 2018. Pirelli estimates a performance step of 0.8 seconds from the new soft tyre to the medium.
At the other end of the spectrum, the relative performance of the hard tyre is less clear. Isola said there was insufficient data at this point to make that appraisal.
"We don’t have a lot of data because it was used just [Thursday] by Mercedes and Sauber," he explained.
No teams at all ran on Pirelli's new ultrahard compound. Even so, teams were impressed by the mileage they had achieved on the resurfaced track.
“The teams were able to comfortably complete more than 100 laps each per day,” said Isola. "The biggest change was the fact that the track has been resurfaced this year, making it smoother with more grip.
"[It] has completely different properties compared to the old one,” he confirmed. “The old one was quite abrasive with a lot of degradation, a lot of wear, suitable for the harder compounds.
“This tarmac is much smoother, but with a very good level of grip. That means we have less degradation and less wear."
Graining hadn't been an issue here last year, but proved to be in evidence again in this year's test.
“We had some blisters, we had some graining,” Isola confirmed. “Graining is new compared to last year, last year we didn’t have any.
“I feel that the new tarmac is generating a little bit of graining because it’s smooth and you have some sliding on the front left.
“Blistering is not a surprise considering the energy the new cars are putting on the new tyres."
Pirelli will be bringing soft, supersoft and ultrasoft tyres to the first race of the season. The ultrasoft won't make its bow until Canada.
“The next stop is the Australian Grand Prix," Isola added. "[It] will give us our first look at the 2018 tyres in a competitive context.”