PARIS (REUTERS) - Seven-times world champion Lewis Hamilton defended Pirelli on Thursday (June 17) after Red Bull rival Max Verstappen said he was unhappy with the Formula One tyre supplier's explanation for a blowout that cost him victory at the Azerbaijan Grand Prix.
Verstappen, the championship leader, 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.
Pirelli have ruled out any production or quality defects, identifying running conditions as the main cause with the two teams operating on lower tyre pressures than others during the race without breaching any rules.
Lower tyre pressures can translate into improved performance.
Pre-race minimum tyre pressures are set but teams have ways of stopping them rising as much as expected once the cars are running.
Mercedes driver Hamilton told reporters at the French Grand Prix that safety was a priority and Pirelli and the governing FIA needed to police things better.
"Whenever there is a failure they always put the pressures up, so that tells you something," he said.
"More often than not the tyres are not running at the pressures that have been asked.
"I think they (Pirelli) have done a great job with the tyres this year, they are more robust than before.
"In this particular instance I don't think Pirelli are at fault."
Verstappen said he was not happy with Pirelli's explanation.
"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 per cent 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.
Pirelli's F1 head Mario Isola told reporters that a standard sensor would be introduced next season but the company did not currently have the tools to measure pressures during the race as well as when the tyres went on the car.
He said predicted running conditions in Baku, based on simulations, had differed from actual ones.
"We didn't achieve these conditions, not because teams were doing something against the regulations but because they were looking as usual for performance and that created a different scenario to what we were expecting," he said.
"The different scenario was that mainly the tyres were running at a lower pressure compared to expectation."
Isola said he would attend the drivers' briefing at Le Castellet on Friday to address any questions.