F1 teams imposed maximum tyre life stint for Qatar GP

The FIA and tyre supplier Pirelli have been forced to impose a maximum stint for all compounds for the Qatar Grand Prix.

Concerns were raised following the sole practice session at the Lusail International Circuit on Friday when, following analysis by Pirelli, it was discovered there was “separation in the sidewall between the topping compound and the carcass cords of the tyres”.

Pirelli confirmed it would conduct further analysis following Saturday evening’s 19-lap sprint event, which would determine what action to take for the grand prix.

However, the FIA has stated that “due to the frequency of safety car interventions in the sprint, the tyre data available for analysis by Pirelli was insufficient to add to that already undertaken following previous track sessions”, although there were some instances of the initial onset of separation.

As was the case in practice, it has been determined the issue was likely caused by the high-frequency interference between the tyre sidewall and the 50mm ‘pyramid’ kerbs used extensively at the circuit, aggravated by the propensity of the drivers to ride those kerbs.

This is despite the fact that ahead of the sprint shootout, the track was narrowed through Turns 12 and 13, in particular, by 80 centimetres.

As a consequence, it has been decided by the FIA and Pirelli, and after consultation with the teams on safety grounds, that a number of measures will now be implemented for the 57-lap main race.

It has been determined that:

* A mandatory limit of 18 laps of total tyre life per set will be imposed.

* The life of already used tyres will be taken into consideration.

* The FIA and Pirelli will communicate to the teams the remaining available laps for each set of used tyres at their disposal for the race and the criteria used to calculate that number.

* There is no direct mandate for at least three tyre-change pitstops during the race, however, this will be a consequence of the above guidelines should the race run its entire race distance.

* Any car deemed to have exceeded the tyre life lap limit will be reported to the stewards as being run in an unsafe condition.