Title rivals Lewis Hamilton and Max Verstappen have disagreed over the results of the inquiry into the tyre failures at the Azerbaijan Grand Prix.
Hamilton said: “In this particular instance, I don’t think Pirelli are at fault.”
But Verstappen, who suffered one of the tyre failures, said: “They have to look at themselves.”
Pirelli concluded the conditions in which the tyres were being run were at fault.
The Dutchman added: “We didn’t do anything wrong, so they cannot put the blame on us.”
Verstappen’s Red Bull and Lance Stroll’s Aston Martin both suffered almost identical left-rear tyre failures in very similar places at close to 200mph on the main straight of the Baku track.
Pirelli said “there was no production or quality defect on any of the tyres; nor was there any sign of fatigue or delamination” and said that the failures were “related to the running conditions of the tyre”.
Pirelli did not explicitly blame any teams for the blow-outs but new protocols have been introduced by governing body the FIA for this weekend’s French Grand Prix. These include more stringent checks on both tyre pressure and temperature – including after tyres have come off the cars.
The implication of the findings is that they believe some teams have been finding ways of controlling tyre temperature and pressure that Pirelli had not accounted for in their calculations regarding the safe conditions for the tyres.
Teams and drivers have long believed the pressures are too high, and lowering them is a performance advantage. But Pirelli uses pressure to safeguard the structural integrity of the tyres.
Hamilton said: “Safety is always the priority and for me and my team there have been clear rules and guidelines as to where we have to operate, so I was very surprised to see they had to clarify those. Obviously you can take what you want from that.
“I am happy they have acknowledged they need to clarify it and what’s really important now is how they police it because they have not been policing how the tyres have been used, pressures and temperatures, and we need to be better. It is great they have done a technical directive but we need to see them follow through and be vigilant.
“Whenever there is a failure, they always put the pressure up so that tells you something – more often than not the tyres are not running at the pressures being asked.
“We didn’t have a problem with our tyres. I think they have done a great job with the tyres this year, they are more robust than before.”
Verstappen said: “They explained they don’t have measuring tools in the race, but we gave them our pressures and they were within the limits they set. If those limits are not correct, there is nothing we can do about it.
“And also Aston Martin didn’t do anything wrong so they cannot put the blame on us.”
Aston Martin driver Sebastian Vettel added that his team had also followed the guidelines.
Asked if he had confidence in the integrity of the tyres, Vettel, a director of the Grand Prix Drivers’ Association, said: “I can’t say 100% yes and I can’t say 100% no.”
Vettel added: “The stress on the tyres is high but it is a product that should be designed to be as safe as possible but in the past we have had plenty of occasions [when the tyres have failed].
“The priority for us drivers is that the tyres are safe and every other interest will always have to come second.”
Red Bull driver Sergio Perez added: “It is a concern. We know Baku is a special place but still it’s a concern what happened.”
The title fight
Verstappen’s accident cost him victory and a chance to extend his four-point championship lead over Hamilton, but he said his strongest feeling after the race was that he had been “quite lucky to hit the wall on the right”.
Verstappen added: “If I would have gone left, it would have been quite a big impact. Of course I was sad and disappointed to not win the race but on the other hand I was like, ‘Wow, I was quite lucky there in that incident.'”
Verstappen’s incident led to a red flag and at the re-start Hamilton cost himself when he locked up at the first corner and slid into the escape road, dropping from first to 15th place and out of the points.
The incident happened because he had accidentally knocked a button in the cockpit – known within Mercedes as “magic” – that shifts the brake bias almost completely to the front for warming tyres on slow laps.
“I don’t even count it as a mistake,” Hamilton said. “I don’t know what the one before that was. I don’t feel any pressure. I feel pretty relaxed. You can’t always be perfect.
“It was an unforced error, something we had that was sitting there that could have happened at any point, and unfortunately bit us pretty hard.”
He said the team had made changes in the cockpit to try to prevent the same thing happening again.
“We haven’t moved [the button],” he said, “just put a shroud around it to make sure I can’t accidentally touch it in future. That’s for the short term – the wheel is not so easy to move buttons so we will look for a longer-term solution in the future.”