Managing the tyres and finding clean air will be central themes to the teams’ strategy plans for Sunday’s grand prix, with the shorter Sprint pointing to it being incredibly difficult to look after your tyres in race trim and while running in the pack.

Pirelli noted graining as the main problem for the drivers. Graining occurs when small parts of the rubber tear off the tyre’s surface as it’s put under excessive stress. These smaller marbles then restick to the surface, altering the tyre’s contact patch and the grip the driver can expect. It’s crucial to manage where possible, as otherwise it can result in degradation, as was seen in the Chinese Sprint.

Looking at the fuel corrected lap times reveals just how excessive this graining was for some drivers – the steeper the gradient, the stronger the tyre degradation is as the stint advances. Lap time is marked on the y-axis on the left-hand side: the lower a driver’s line, the faster their laps were, giving us insight into the pace-tyre relationship with the fuel effect removed.

As expected from what was seen on track given his emphatic win of the Sprint, Lewis Hamilton managed his graining and degradation well out front in the clean air. Being in ‘dirty air’, or following other drivers in a pack, means turbulent air flows over the car and its wings, impacting the level of downforce it has. With less downforce, there’s less traction, resulting in tyre slip, tyre heating, and graining. 

Those running in the midfield and battling hard on the used medium tyre suffered higher degradation generally as a result of this effect. This can be seen particularly for Doohan, who spent almost his entire Sprint following other cars, and for the Kick Saubers of Hulkenberg and Bortoleto, as examples.

Pirelli’s reaction to the conditions

The circuit’s new surface for this year has offered up some quirks in terms of grip and therefore its effects on the tyres. While it’s smoother, faster and grippier than before, the resurfaced Shanghai circuit is also ‘peakier’, making it tough for the drivers to get into and stay in the correct operating window. 

Coming into the weekend Pirelli’s simulations, created using data from the teams themselves, had predicted a lap time reduction on previous years but not to the extent that has actually been seen. As a result of the lap times on Friday,  Pirelli raised the minimum starting pressures on all four axles overnight, with the front moving to be 27.5psi and the rear to 24psi. 

“Rarely have we witnessed such a significant improvement in times with the same car technical regulations,” said Pirelli’s Chief Engineer, Simone Berra. The “really surprising” grip levels coupled with the teams’ abilities to lower their ride heights on the smoother surface created a considerably quicker lap which placed higher stress on the front left tyre particularly. By increasing the tyre pressures, Pirelli are looking to help the tyres cope with the increased load they’re under by increasing their structural rigidity.

Managing the degradation and pace

How much pace a driver has over the grand prix will come down to how well they can manage their tyres compared to those around them, with the Sprint again giving us some insight into how they fared over 100km.

It’s important to note that the teams could make setup changes between the Sprint and grand prix qualifying based on what they learned from the single lap and race runs. As a result, this pace order is likely to change, as we’ve already seen with the Sprint Qualifying order and how the grid will look tomorrow.

Ferrari emerged as the quickest team on average over the 19 lap Sprint, largely influenced by Hamilton’s superior tyre management. That said, Leclerc wasn’t far off his teammate, ranking fourth quickest.

McLaren rank second after Lando Norris suffered considerably with his tyres running in the middle of the group after making an error in the first few corners. The impact of this on his relative pace to his team mate is clear to see with Piastri ranking P2 while Norris is P8.

Verstappen showed solid pace but also a wider range of lap times than was seen for others in the top five, which coupled with his fuel corrected lap times, supports his comments about “really struggling for grip”. Combined with Lawson’s pace after a traffic-filled race starting P20, and Red Bull sit outside the top five for team pace.

Russell’s top five pace has pulled Mercedes’ average into the top three despite Antonelli finding the management more challenging, as is perhaps to be expected from the rookies.

How will the strategies look?

The impact of track position on tyre degradation will be a critical consideration for the teams when running the full grand prix. With a single pitstop mandatory, but more also likely in light of this high degradation, timing these to allow the driver to emerge from the box in clean air will be sought after. Getting it wrong and releasing the driver into traffic will have significant consequences for tyre wear and therefore pace.

Pirelli believe the one stop is out of the question due to the degradation levels, with a two stop thought to be “obligatory” by Mario Isola, Pirelli’s Motorsport Director, making use of the medium and hard compounds.

“Although the new soft is fairly close to the medium in terms of performance, we don’t think it’s a valid choice, even if it could offer more grip off the start line. 

“In fact, those starting near the back might go for the hard to extend the first stint as long as possible, before making up places in the run of pit stops.”

Every driver in the field has two new sets of hard tyres and two sets of mediums available, with the age of these varying by driver. Lawson, Ocon and Hulkenberg all have two brand new medium sets remaining which could open up the three stop strategy for them as they look to make their way up the order from P20, P11 and P12, respectively.

Pirelli have predicted a medium-hard-hard strategy to be optimal, with a medium-hard-medium also feasible, perhaps more so for those drivers who have access to two sets of fresh mediums.