When the tiniest of margins can count for so much in Formula One, it’s unsurprising that 0.4 millimetres of tyre tread became a major sideshow at the Spanish Grand Prix.
Pirelli’s tyres have attracted a wide range of controversy in Formula One from the moment the Italian company won the contract to become the sport’s control supplier from the 2011 season, but lost in the sledging is the fact that Pirelli operates in Formula One under the guidance of the sport itself, which has directed the company throughout its tenure to make rubber compounds to suit particular purposes.
At first Pirelli’s brief was to construct high-degradation tyres, but over time the instructions have been tempered down to create compounds that enable drivers to push harder for longer.
The current brand of tyres is still manufactured to have a limited life span, however, which means mastering them on the sport’s variety of track surfaces and in a broad array of climatic conditions is still a major part of the racing challenge for constructors.
In 2018 this was obvious as early as in preseason testing, where some teams reported blistering — an overheating of the tread closest to the tyre carcass that causes the rubber to bubble up and destroy the surface — despite the wintery conditions in late-February Barcelona.
After testing Sebastian Vettel dismissed blistering concerns as posturing by teams that had failed to understand the tyres — “I think it’s quite normal that … every team tries to get the tyre supplier to go in the direction that suits their car best. We think Pirelli has done a good job with their compound selection,” he said — but Pirelli responded nonetheless.
For the Spanish, French and British grands prix, run at tracks featuring similar surfaces, Pirelli would reduce tread thickness by 0.4 millimetres.
Lo and behold Mercedes dominated the Spanish Grand Prix, claiming its first pole position since the season-opening Australian Grand Prix and winning on merit for the first time all season.
Vettel had no doubt about the cause.
“I think it’s pretty straightforward,” he said after qualifying third behind the Mercedes front-row lockout. “The tyres are different.”
The seemingly insignificant change had been the motivator for a bubbling undercurrent of discontent for some time, however, with Auto Motor und Sport reporting that Mercedes had approached Pirelli to suggest a tyre change after struggling particularly badly during testing, to the chagrin of an assortment of other teams.
But Toto Wolff refuted the claims that the changes were made to benefit his team.
“Rubbish,” he said. “All teams had blistering, very heavy blistering, at the test in Barcelona. “The tyres wouldn’t have lasted in the race.
“So I don’t know where suddenly this rumour comes out that we have been influencing Pirelli and the FIA to change any tyres.”
Ferrari team principal Maurizio Arrivabene wasted no time in making his rebuttal.
“There is a difference between being consulted and being informed,” he told Italy’s Sky Sport. “We have been informed, not necessarily consulted.”
With Ferrari unable to execute the same one-stop strategy pulled off with such relative ease by Mercedes, effectively counting Vettel out of victory and, later, podium contention, the sourness is sure to continue through to next month’s French Grand Prix and July’s race at Silverstone, especially if the Scuderia were to resume its advantage at the intervening races.
But is there really a case for Pirelli to answer?
As usual, the Italian tyre manufacturer is caught between a rock and a hard place. On the one hand it is deliberately producing tyres that are difficult to master but on the other hand it wants to ensure its products perform strongly and safely.
Safety won out in Pirelli’s decision making, with the tread thickness change made on safety grounds given sever blistering is potentially a safety issue — think back to the 2011 Belgian Grand Prix, where Red Bull Racing and Pirelli became embroiled in a war of words over the integrity of a set of blistered tyres, as a good example of this.
Indeed Pirelli head of car racing Mario Isola emphasised it was his company’s decision alone to request the change in an attempt to improve safety without diminishing spectacle by simply bringing a harder set of compounds to the problematic circuits.
But the optics of Mercedes pushing for a change that has ultimately benefitted it in both tyre life and seemingly also pure performance terms has turned what should have been a minor technical tweak into a potential championship sore point between the two biggest-hitting teams on the grid.
The perception of the scenario is everything, and as is almost always the case, Pirelli has ended up looking the bad guy for just trying to do its job.