Max Verstappen unhappy with Pirelli blowout explanation

Formula One world championship leader Max Verstappen said on Thursday he was unhappy with Pirelli's explanation for the high-speed tyre blowout that cost him victory at the Azerbaijan Grand Prix.

Red Bull's Verstappen suffered a left-rear failure on the straight while leading towards the end of the June 6 race in Baku.

Aston Martin's Canadian Lance Stroll had earlier crashed out with a similar failure.

Sole supplier Pirelli on Tuesday ruled out any production or quality defects and accepted the teams had followed prescribed parameters when the tyres were fitted.

It indicated that how the tyres were then run had contributed to the incidents.

Asked at the French Grand Prix if he was happy with Pirelli's explanation, the 23-year-old Dutch driver replied: "Personally not.

"I think the team did everything like they should have done, they followed all the guidelines with tyre pressures at the start.

"For sure we'll go up on pressures here for this weekend. 100% sure we will. Probably it has something to do with that, what happened in Baku, but it would also be nice to know if it was tyre pressure-related. Just speak out.

"That would be a bit easier to understand than the explanation we got so far."

Pirelli had said in their statement that the cause was due to "a circumferential break on the inner sidewall, which can be related to the running conditions of the tyre."

Verstappen said he felt fortunate to have escaped unhurt from the crash.

"I was actually quite lucky to hit the wall on the right hand side, instead of the left. I think if I would have gone left it would have been a really big impact," he said.

Speaking later on Thursday, Pirelli motorsport boss Mario Isola gave further explanation of how the failures occurred, claiming the running pressures on the two cars were lower than expected once they were on track, creating extra stress on the shoulder of the tyre and resulting in the failure.

He reiterated that neither team had broken the rules regarding tyre pressures as they met the minimum pressure when the tyres were checked before they went on the car, but that the pressures had not reached the pressure Pirelli expected once they were on track -- something that will be regulated next season but is not currently monitored by the FIA.

"In the regulations it is not written what is the running pressure that you have to respect," Isola said. "So I cannot say we are doing something against the regulation in search of more performance because if they respect the starting pressure, at the moment, they are complying with the regulations.

"If the same thing happens next year, with a standard sensor [supplied by the FIA], and we have imposed a [minimum] running pressure, in that case they would be against the regulations. But this is not the case this year, and is not possible to do that simply because we do not have a sensor where we can rely on measurement.

"Obviously, each team is looking for performance. They are here racing, they are not here just to cruise around the track. And that means, looking for performance, we know that if you go for a bit lower pressure you will get some performance.

"That means they are looking for performance and the running parameters were not in line with our prediction."