Formula 1 teams and tyre supplier Pirelli have arrived at this weekend's Brazilian Grand Prix braced for a more unpredictable weekend than normal.
While the track layout itself is unchanged from previous years, what is different is the asphalt – which has been completely resurfaced since last year's event.
Newly laid tracks add a huge degree of uncertainty at grands prix, as teams are never sure about the impact it can have on grip levels.
At some venues in the past – perhaps most famously Turkey in 2020 – if the track has not been treated properly then it can trigger a massive drop in grip and cause huge headaches for drivers and teams.
At the other end of the spectrum, a new surface that offers some decent grip but has not been rubbered in can result in cars sliding a bit more, which has a negative impact on tyre degradation.
What Brazil will deliver is hard to be sure of right now, with the final answer only coming from the first practice session when drivers get to run out on track for the first time.
As Alpine's Esteban Ocon said: "This weekend there's new challenges ahead, a lot of unknowns for everyone, looking at how the tarmac is and the degradation. How it can be and the grip level? We don't know."
What the first data says
There are some early signs though of what to expect – and it points towards an especially exciting F1 weekend.
Early analysis from Pirelli's engineers of the Brazil surface shows that there are no major alarm bells ringing over the grip on offer.
Motorsport.com has learned that the micro-roughness of the Interlagos surface shows a 46% drop compared to last year, with macro roughness indicating a 30% drop.
That would point towards the track in theory offering less grip than last year, which could result in more sliding and therefore higher tyre temperatures and more degradation.
But a deeper dive into the overall grip levels, based on the chemical adhesion interaction of the track/tyre, has shown that the situation is not actually too different to previous years.
Brazil has traditionally not been a venue that offers a lot of grip, and some of the data collected ahead of the weekend suggests that some corners may actually be an improvement on before.
The darker surface
This first snapshot of data points then towards the new surface maybe not leading to a dramatically different weekend.
However, there is another interesting element that has popped up and could actually have the biggest impact on how things turn out – and that is the colour of the new asphalt.
The new surface is very black, and that means that it will absorb the sun's temperature much more than the old washed-out grey surface that was used up until last year.
Pirelli's first analysis of the variation in temperature of the track surface has already pointed to things being quite dramatic – and the early afternoon on Thursday had already registered it nudging towards 60C.
Higher track temps have a direct impact on tyres temperatures, and can help amplify any thermal degradation – which is always a factor around the Interlagos track because of its layout.
The higher temps could then force teams to shift towards the harder compounds for both the sprint and the grand prix, but this choice is slightly complicated by the selections on offer this weekend.
First of all, Pirelli has opted to shift its compounds one step softer than last year, so the 2023 soft is the 2024 medium.
Then secondly, with Brazil being a sprint weekend, the tyre allocation is different – with two sets of hards, four sets of mediums and six sets of softs available.
The likelihood is that the 2024 soft is not going to be a suitable race tyre – so is only really good for qualifying.
That then means teams are going to have to manage very carefully how they distribute their tyres across the sprint and the main grand prix – knowing full well that they cannot compromise what they need for Sunday.
What teams will need to understand quickly from practice is if the medium is going to hold on enough for the 24 laps of the sprint. Last year that tyre (which was the soft in 2023) did cope - but if degradation is worse this time around it could make things difficult.
If the medium isn't good enough, then that could make life extremely complicated for the race that is normally a two-stopper.
If teams need to run the hard in the sprint, then that would leave them short for the grand prix – so Saturday could be especially intriguing.
What this all means is an especially complicated race weekend and one where rain could yet throw extra uncertainty into the mix.
