Why Imola F1 race is the acid test for radical tyre plan

Pirelli’s greatest challenge since becoming Formula 1’s sole tyre supplier in 2011 has been to reconcile its brief – to deliver tyres whose performance drops off sharply beyond a given point – with the drivers’ desire to have rubber which they can push on through an entire stint. These two requirements might not be mutually exclusive but the ‘sweet spot’ between them is hard to find.

Nobody, least of all the drivers, wants to have races which settle into long processional phases where nobody dares push for fear of degrading their tyres faster than rivals. When overtaking is difficult – either because track layout militates against it or car performance is too closely matched – guarding track position becomes the strategic imperative and teams look to minimise the number of pitstops they have to make.

This year Pirelli has given drivers more of what they wanted by adjusting its compounds to be more resilient – and the effect, in combination with car performance converging, has been more one-stop races with less strategic variation. At several rounds the difference in life and lap time between the hard and medium compounds has been so small that it has all but eliminated the strategy of, say, extending a stint to build a tyre offset for later in the race.

Presently it’s mandated that three dry-weather compounds – marked hard, medium and soft – are brought to each round. Until this year these were drawn in sequence from a pool of five, officially named C1-C5, depending on the requirements of the circuit.

The processional nature of the Japanese Grand Prix alarmed all the stakeholders, prompting Pirelli to suggest a solution: ‘skipping’ compounds so there is a bigger step in tyre performance. This could push teams towards two-stop strategies or introduce an element of peril in sprint weekends, forcing them to make difficult choices and potential sacrifices.

But it all hinges on the performance of the C6 tyre – new for this year and, so far, tested but not raced. At Imola it will be in the mix of potential choices for the first time, and the data gathered here – provided the weekend is largely dry – will inform Pirelli’s decision to take its compound-skipping plan forward or not.

As Pirelli motorsport boss Mario Isola explained during the Miami weekend, the current compounds cannot be changed during the season, so the company had to find other levers to pull.

“We need to understand if there is any other possible approach in tyre selection to push them [the teams] to have a two-stop strategy,” he said.

For Imola, Pirelli is bringing the softest choices of the season so far – the C6 was originally envisioned as a super-soft option for street circuits. What Pirelli wants to avoid is the fate dealt to the ‘hyper-soft’ compound introduced in 2018: used for the first and only time in Monaco, it failed to deliver the anticipated result as the entire grid plodded around, several seconds a lap off their qualifying times, to avoid having to stop more than once.

Pirelli’s view is that it needs to see how the C6 performs in race conditions because all it has now is test data which is less representative.

“Hopefully, if it’s dry, [the aim is] to get data on the C6,” said Isola, “and then try to simulate again other races to see if skipping one level [will work] – for example, between C3 and C4 the delta lap time is quite close, maybe we can consider C2, C4 and C5.

Mario Isola, Racing Manager, Pirelli Motorsport, talks to the press

Photo by: Andy Hone / Motorsport Images

“That means that if you want to go on a one-stop C2-C4, the C2 is obviously slower, so you shouldn’t have the same advantage as if you nominate C3, C4 and C5.

“In some other cases we can consider to use C3, C5 and C6. Or C2, C4 and C5. So Imola is critical because we need additional data on the C6.”

For Monaco this year, two stops have been made mandatory, but this is unlikely to be adopted across the board because it would likely lead to all teams running broadly the same strategies and stopping at the same point. What the stakeholders want to achieve is a scenario where there is more strategic variation and where the optimal choices are less obvious – so there would be a mix of one and two-stop strategies, possibly even three.

Achieving this is best done by encouragement than force.

The attendant risk of having more separation between compounds is that one becomes the de facto qualifying tyre and is never used in race conditions. Pirelli has been working with the commercial rights holder to simulate potential outcomes and mitigate this risk.

“We can also do C1, C3 and C5,” said Isola. “I’m not sure about the result, but we can do that.

“We [would] never decide it ourselves. We make a proposal to the FIA and F1. We share the proposal with the teams and then we come to an agreement with the approval of the FIA.

Some of F1 and Pirelli’s simulations have involved exploring whether it would be possible to force teams into difficult trade-offs during sprint weekends – perhaps sacrificing some performance in the sprint to have a more optimal tyre selection for the race. Whether these scenarios could actually be engineered, given the teams’ simulation capabilities, is another question.

“It’s a never-ending story,” said Isola. “We try to create an issue to the teams, and they find a solution…”