Formula 1 could mandate a minimum of three pitstops for Sunday's Qatar Grand Prix after the discovery of a tyre wear issue following Friday practice at the Lusail venue.
The championship's sporting body, the FIA, has announced that "a separation in the sidewall between the topping compound and the carcass cords" was discovered by F1's tyre supplier Pirelli on tyres that had been used for around 20 laps after the sole practice session of the weekend.
It is understood Pirelli then notified the FIA's single-seater chief Nikolas Tombazis, leading to a set of contingency measures being worked out.
The FIA and Pirelli say that putting further mileage on tyre compounds "could result in circumferential damage of the tyres with subsequent air loss", and they believe the 'pyramid' kerbs installed at the venue - and more specifically "the high-frequency interference" between the tyre sidewall and these kerbs - are the culprit.
F1 has now delayed Saturday's sprint qualifying in Qatar by 20 minutes in order to fit in a 10-minute mini-practice session at the original start time.
This is because it is revising track limits at the high-speed Turn 12 and Turn 13 - two right-handers in which the current racing line has F1 cars riding the outside kerb quite substantially.
For those corners, the white line delineating the edge of the track will be moved by 80 centimetres for cars to avoid the highest point of the kerbs.
Turn 14, another quick right-hander, is also being monitored as a potential problem point.
New Saturday Qatar GP schedule
4.00pm - Practice Familiarisation Sesssion (10 minutes)
4.20pm - Sprint Shootout
8.30pm - Sprint
If the issue is still evident following a post-sprint analysis (the sprint race spanning 19 laps), the FIA will mandate that tyre sets are not taken beyond a 22-lap total lifespan at any point in Sunday's 57-lap race.
That number will be 20 laps for fresh sets, with the extra two allowed for those sets that had already been used earlier in the weekend, to account for the minimal amount of inlaps and outlaps.Listen to "S2 E10: Inside the chaos of F1's Indianapolis 2005 farce" on Spreaker.
It will also mandate "three tyre-changing pitstops", meaning teams would be further discouraged from trying to stretch sets close to that 20/22-lap limit.
No extra sets of tyres will be introduced into the pool.
The FIA says it and Pirelli "will carry out extensive research and simulations in order to establish with complete confidence the reasons behind this issue, and to work on solutions to avoid it in the future".
The Race understands that the problem had gone undetected during the session, but that signs were evident across the board in Pirelli's post-session analysis - with the issue worse on the left-side tyres because of track configuration but present on the right side, too.
The sprint format has contributed to the exact situation and the potential extreme measures, as there hadn't been the usual long runs normally seen in Friday's second session, which would've presumably permitted a clearer picture to form.
The Qatar GP, which is being held for a second time, had already featured headline-grabbing tyre problems back in its first edition in 2021, with a spate of late-race tyre failures that Pirelli had attributed to excessive kerb use.
But given kerb changes and a resurfacing this new problem had not been anticipated for the 2023 weekend, as the various developments meant it was guesswork as to how cars would ride the kerbs.