Pirelli: P Zero Medium and Soft tires for the Circuit of the Americas

Pirelli – The Circuit of the Americas, in Texas, is one of the newest tracks in the Formula One, having only been inaugurated in 2012. For the first time, Pirelli has decided to bring medium and soft compounds here (in previous years it had brought hard and medium compounds).

This versatile choice for 2014 aims to cope with the diverse demands of the track, characterized by three long straights and numerous technical corners. These include Turn 1 – a constant radius hairpin that puts a lot of energy into the tires – and other corners with quick changes in direction, which are a bit reminiscent of Silverstone or Suzuka.
With its 20 corners and various variations in altitude, Austin is a truly challenging track: think, for example, of the uphill braking after the start which makes it difficult to find the right braking point. These elements make it a truly exciting circuit, loved by both drivers and spectators.
After the United States, the teams will move directly to Brazil to compete on November 9th at Interlagos, a circuit for which the same choice of compounds was made: medium and soft.

Paul Hembery, Pirelli Motorsport Director: “America is a key market for Pirelli. So we are really happy to return to Austin which, in addition to being a great city, is also a fantastic place to race. The track is now three years old, so it should theoretically offer greater grip than previous years. With the medium and soft tires we expect two stops, but we will have to wait for free practice to confirm our predictions. Much will depend on the weather conditions. Although the race takes place in November, warm but variable conditions are expected: thermal degradation will, therefore, be an important factor. How much this will influence the general degradation and wear, and therefore the race strategy, also in light of this year's new generation of cars, we will only find out there. In recent years, a one-stop strategy has always proved successful, also because the race comes relatively late in the season, by which time most of the teams have understood how to get the most out of the tyres."

Jean Alesi, Pirelli technical consultant: “Austin is above all an exciting circuit for the drivers. The braking at the end of the climb after the pits and its hairpin to the left offer opportunities for attack. Even the 's' that follow allow for different lines and the possibility of inventing something with a view to attacking a competitor. It's not a boring track: there are plenty of opportunities to overtake it and this is a technical fact which in itself is a guarantee of interesting Grands Prix. In Austin there is also another important technical fact to keep in mind: the notable variation in temperature that can be encountered there. In past years, it has also been quite cold early in the morning; but with the sun you can get to qualifying time with very heat on the track. This can make it complex to identify the ideal window for using the tire: a challenge for teams and drivers that adds to the many already present on each circuit."

The circuit from a tire point of view:

The three long straights tend to cool the tires, making braking areas critical. This also has effects on entering fast corners, as the compounds have to return to temperature very quickly.

The P Zero White medium is a "low working range" tyre, capable of achieving optimal performance even at low temperatures. The P Zero Yellow soft, on the other hand, is a "high working range" tyre, suitable for higher temperatures.
During last year's US Grand Prix we saw a wide variety of temperatures: from 18 to 37 degrees centigrade.

The combination of straights and curves requires a good compromise in terms of downforce, placing a strong emphasis on the mechanical grip of the tyres. In addition to the long Turn 1 and the fast direction changes in the first part of the lap, Turn 11 is also very demanding on the tyres.

The drivers begin to brake when the cars enter the corner, resulting in an irregular distribution of loads on the tires.

Last year's winning strategy was one stop: Sebastian Vettel, Reb Bull, started on the medium compounds and then switched to the hard tires on lap 27. The first 12 drivers made just one stop.