Formula 1 teams shifted their Friday practice plans at Sepang toward long runs and tyre management after the poor track surface contributed to substantial degradation. The FIA put the chance of rain ahead of second practice at 90 per cent, prompting several teams to move long-run work earlier. The conditions left teams with limited information for qualifying and an unsettled picture of possible strategies for Sunday’s race.

Practice for the Formula 1 Bahrain Grand Prix in Malaysia was unusual in several ways. Lap times were four and a half seconds slower than expected, Mercedes did not look as strong as anticipated, and teams departed from their usual session routines. The surface was poor, and the resulting low grip contributed to tyre wear that became a central concern in their Friday work.

Drivers typically complete qualifying simulations around the midpoint of the second practice session, then use the remaining time for longer race runs. With rain considered likely before FP2, multiple teams brought those longer runs forward to protect the chance to gather race data. Red Bull driver Max Verstappen was among those who changed his schedule.

“I wanted to do a long run in case there was some rain coming in,” Verstappen said when asked to explain his Friday plan. Red Bull technical director Pierre Wache said the team wanted to preserve its long-run programme, which he considered the weekend’s most important work because of the degradation and uncertainty over tyre behaviour.

“We didn't want to compromise the long run, which I think is the most important thing this weekend, in terms of degradation and see how the tyres behave, especially the medium. We didn't have data of the medium, so we prioritised that and afterwards it was too late to run the soft,” Wache said. The team prioritized collecting information on the medium tyre, leaving no time afterward for a soft-tyre run.

That choice also illustrates why Friday’s individual lap times in Kuala Lumpur offer little indication of the competitive order. Long-run performance gives teams a more useful basis for judging the weekend, so the Friday classification carries even less weight than it normally would. The teams’ immediate task was to understand tyre wear and temperature behaviour over sustained running.

The emphasis differs from a typical race weekend, when teams balance qualifying speed against preserving tyres, particularly at the rear, for the race. At Sepang, the unusually high degradation has made race pace the stronger priority. Simone Berra, Pirelli’s chief engineer, said the level of wear recalled just one other weekend to him: Barcelona.

“We have seen today that the degradation was quite significant, quite high. I remember just one weekend where we had this kind of degradation and that was Barcelona,” Berra said. Pirelli recorded tyre degradation of around two or three tenths of a second per lap on both the medium and soft compounds. He said teams would need to manage rear temperatures in particular, while also looking after the front tyres through the circuit’s high-speed corners.

The low grip from the poor surface can intensify the problem. Sliding raises the tyres’ surface temperatures, and hotter surfaces produce less grip, which can lead to more sliding and still higher temperatures. Pirelli described the sequence as a cycle that teams will need to avoid as they try to control thermal degradation.

The rear axle is the main concern at the rear-limited track, but front tyres also need attention. Managing the two ends of the car at the same time is difficult, Berra said, because drivers must avoid sliding in high-speed corners and under acceleration while maintaining a consistent pace and not overloading the fronts.

“The point is that for the rear axle especially, there is no rear respite here. It's very difficult to keep the temperatures under control, you have to try to avoid sliding in the high-speed corners and on traction,” Berra said. “But meanwhile you have to keep consistency with the pace and you have to avoid overloading the front tyres.”

He said the front tyres could also overheat and degrade, leaving teams with a compromise over which axle to protect most. Berra expected teams to focus on the rear because losing performance there has a greater effect than losing it at the front. The challenge is to maintain pace without pushing either end of the car beyond a manageable temperature range.

The data gathered Friday also means teams’ evening analysis will differ markedly from their work after the Azerbaijan Grand Prix a week earlier. Baku had very low degradation and placed a high premium on starting near the front. At Sepang, the greater tyre wear makes qualifying position less decisive because drivers who preserve tyre performance may extend a stint or push harder than rivals.

“Baku was a circuit with very low degradation levels and very high importance of qualifying on the front rows. Here, qualifying is less important,” Berra said. “We know that it's possible to overtake, especially when you have this high degradation. If you are able to keep the performance and the tyre temperatures in the correct window, you can extend or you can push more than other competitors. The position on the grid is less important than in other places.”

The focus on race pace has left teams with more unanswered questions than usual heading into qualifying, even if the session is dry. Berra said some teams had struggled on Friday to bring their tyres up to temperature by the first corner of a flying lap. That difficulty arose despite the extremely high track temperatures, as teams prioritized protecting the rear axle for race conditions.

Sunday’s tyre picture is also incomplete. Every team has opted to save two sets of hard tyres as a precaution, leaving no data on the C2, the hardest compound available this weekend. Pirelli therefore has no running information on that tyre either. The usual assumption that harder compounds are better suited to a race may not hold in such extreme conditions.

“I would also expect a high level of degradation on the hard compound, because [a harder tyre] is generating a lower level of grip and therefore a higher level of sliding and higher surface temperature,” Berra said. Friday’s running on the soft and medium had already shown that the softer option could sometimes wear at a similar rate to, or more slowly than, the medium. In some back-to-back comparisons for the race, the medium slid more, while the soft was more controllable.

“It's something that we have seen today with the soft and medium as well. We have seen in some back-to-back comparisons for the race that the soft was at a similar level of degradation or even a lower level of degradation than the medium. That’s because the medium was sliding more than the soft and the soft was more controllable, let's call it this way. And so all options are open for Sunday,” Berra said.

Pirelli expects teams to have several viable choices, with a two-stop race considered likely and three stops also possible. Berra said all three compounds could be used, and the uncertainty over their relative performance could create different strategic combinations. He said that range of possibilities was a result Pirelli wanted from the weekend.

Based on reporting by Autosport.