Pirelli Motorsport boss Mario Isola said that the data gathered by Formula 1 teams on Friday at the British Grand Prix was crucial in understanding a fast evolving track.
The surface of the Silverstone International Circuit was relaid in the close run up to the race week in order to improve drainage in adverse weather conditions.
The fully green track provided plenty of grip in Free Practices 1 and 2 despite light rain early in the day, as well oil and dust working its way to the top of the surface, making it greasy and catching a number of drivers by surprise.
Romain Grosjean suffered two spins in the morning session, one at the pit exit and one at Brooklands, while home driver Lando Norris spun at Club corner.
Sebastian Vettel, Charles Leclerc, Max Verstappen and reigning world champion Lewis Hamilton were among the high-profile drivers sliding off the track as wind added to the challenge.
“Track evolution was the main theme today,” said Isola.
“A new and greasy track surface [was] one of the unknown factors as the teams embarked on Free Practice, as well as some changed cambers and bumps.
“For these reasons, we saw more spins than usual especially during the morning, as drivers looked for the optimal line.”
Even with the tricky track conditions, Valtteri Bottas‘s fastest Free Practice 2 time of a 1:26.732 was 0.8 seconds faster than Vettel’s pace-setting time in the same session last year – on similar compounds.
Pirelli estimates that the pace difference between the soft and medium compounds will be around 0.7s, with all teams contributing to that data through completed Friday programmes.
“With nobody having run yet on the new surface, it was important to gather as much information as possible today, but it was tough to get an accurate read as the track was evolving all the time, which also makes assessing the performance gaps quite tricky,” Isola added.
“Despite some interruptions in the morning, the teams achieved their objectives, also setting faster times than they did on the older but bumpier surface last year.”