A sixth slick tyre compound will be introduced to Formula 1 from next seasons after concerns from Pirelli over the current C1 version.
The current system has five different compounds, from which three are chosen for each race weekend. They range from C1 to C5, with the latter being the softest and fastest, but least durable. The rubber gets progressively more hard, with the C1 being the slowest to degrade with use but also the slowest in terms of lap time.
From 2023, there will also be a C0 tyre – but that is not the new compound being introduced. Instead, the current C1 will become the C0, while a new compound will be introduced as the new C1 to bridge a performance gap between the current C1 and C2 which Pirelli felt was too wide.
"We have introduced a new C1 compound and have decided to homologate for next year six compounds, not five," Pirelli head of motorsport Mario Isola told reporters at the Abu Dhabi tyre test on Tuesday. "The current C1 that worked quite well at, for example, Zandvoort and Silverstone, we didn't want to eliminate.
"We decided to introduce a new C1 with more grip compared to the old C1, so the old C1 is now the C0 to avoid renaming all the others. We have the new C1 and then the C2, C3, C4 and C5 are the same as this year.
"The new C1 is much closer to the C2. I would say the only target we didn't achieve was a new C3 more in the centre between C2 and C4." Explaining why Pirelli had felt the need to make this change, Isola cited concerns that the C1 was seen as too slow in the 2022 season – which had seen a 30% increase in overtaking manoeuvres.
During that post-season tyre test, 24 different drivers took to the Yas Marina Circuit. Between them they completed 2,458 laps – just shy of 13,000km – and produced a huge amount of performance data for Pirelli to analyse, so the supplier can use its findings to design better tyres going forward.
In the current system, the three tyres chosen for each race weekend are always next to each other on the scale. That means the C3 is always present at every grand prix, and that Pirelli have three choices of sets to approve for an event. With the addition of a sixth compound, Pirelli is also open to leaving a gap between compounds – giving them a far greater choice to suit each track and expected temperature conditions.
"In some cases we can have a step between the compounds we want to select but not always," Isola confirmed. "It's an option we have in our pocket that we keep. I believe we have an idea of what we want to allocate for next season – we want to keep the flexibility to change, or to fine-tune, this allocation according to the result of the pre-season test in Bahrain and the first races."
