Pirelli: New asphalt creates a slippery surface with little grip

Mexico City, October 30, 2015 – A new track always creates unique challenges, with fresh asphalt frequently offering little grip due to oil in the tarmac rising to the surface, and no rubber previously laid down to enhance adhesion.

These factors meant that it was difficult for the drivers to find grip today: a situation that was complicated by the variable track and air temperatures, which culminated in light rain during FP2. Over the course of the afternoon session, the track temperature dropped by eight degrees, making it very hard for the teams to get an accurate read on tyre behaviour.

More rain possible for qualifying and race

The weather in Mexico seems to be equally uncertain for the rest of the weekend, with a possibility of rain for qualifying and the race. All four compounds were run today, although only Williams driver Valtteri Bottas used the Cinturato Blue full wet for an installation lap in FP1. The intermediate, medium and soft tyres were used extensively, with the soft tyre proving to be more than two seconds per lap faster than the medium. This was due to the high degree of track evolution seen today, combined with the effect of rain in the FP2 session. The asphalt in Mexico has a very closed surface, limiting the permeability of the surface.

As usual, the drivers completed longer runs during FP2 on both slick tyre compounds: although it remains to be seen how useful this information will turn out to be. Establishing tyre temperature was one of the biggest challenges, but as the circuit rubbers in and evolves, this will become easier. Toro Rosso’s Max Verstappen was fastest in FP1 on the medium tyre: with nearly seven seconds separating the fastest from the slowest car. In FP2, Mercedes driver Nico Rosberg was quickest on the soft tyre: more than four seconds faster than Verstappen in the morning.

Paul Hembery, Pirelli Motorsport Director: “Today was all about grip and track evolution. As usual on a new surface, there’s a very shiny new top layer of oil and grease that makes it very hard to find traction. As time goes on, the top of the surface eventually gets grated away and more rubber is laid down: but this doesn’t happen instantly. The weather today didn’t help either with very variable temperatures and then rain at the end of FP2.

So this has made what’s already a very hard job for the teams in preparing for a new track even more difficult, because there isn’t enough consistent information to get an accurate picture of what conditions will be like for the rest of the weekend. However, these challenging circumstances bring out the best in Formula One, with the teams having to make the most of limited information to extract the best possible performance. Even though today was just free practice, the atmosphere was absolutely incredible: the stadium section in particular is set to be a highlight of the lap on race day.”

Pirelli