Pirelli: Strategy wide open for the final race of the 2013 season

As the rain continued to fall over Sao Paulo, qualifying for the final race of the 2013 season took place in wet conditions, with the teams all using the Cinturato Blue full wets and Cinturato Green intermediates. Red Bull’s Sebastian Vettel set pole position for the ninth time this season, thanks to a time of 1m26.479s on the intermediate tyre.

Only four drivers have claimed pole position this year – Vettel, his team mate Mark Webber and the Mercedes line-up of Nico Rosberg and Lewis Hamilton – but throughout the last four years, the polesitter at Interlagos has failed to win the race.

So far this weekend, there has been no significant running on any of the slick tyres, meaning that if the nominated P Zero Orange hard and P Zero White medium tyres are used tomorrow, the teams will have no data to go on. As a result, strategies are going to be wide open – with the teams having to react to changing circumstances as they evolve rather than prior information.

The first wet qualifying session since the Belgian Grand Prix in August got underway with spitting rain and ambient temperatures of 19 degrees centigrade. Most cars headed out early in Q1 to set a banker lap, with all the drivers using intermediate tyres. The rain intensified during the session, with an early time from Mercedes Lewis Hamilton topping the Q1 time sheets.

Conditions at the start of Q2 remained similar, which meant that most drivers again went out early, all on intermediates. Vettel’s first run gave him the fastest time, which was then beaten by Lotus driver Romain Grosjean. With the rainy conditions intensifying throughout the session, it was hard for the drivers to improve.

The final top 10 shoot-out was delayed to enable the worst of the standing water to clear. Once the action resumed, the cars started the session on the Cinturato Blue full wet tyres – which can clear 60 litres of water per second at full speed. Vettel was the first driver to set a time on the full wets, with Grosjean the first driver to put on the intermediates. With the track drying, the lap times got quicker towards the end of the session. Vettel set his best time on the intermediate tyres in the closing moments.

Webber went fastest in the final free practice session this morning, again held in wet weather. Drivers used the full wets for most of the session, with Webber the first to use the intermediate. His first intermediate run was good enough for fastest time.

Pirelli’s motorsport director Paul Hembery said: “A wet qualifying session meant that the drivers and teams were dealing with a lot of uncertainties, but they at least had relevant information from the wet running yesterday. The keys to a strong performance were ensuring that the tyres were operating within the correct temperature window, and timing of the fast laps. Being on the right tyre at the right time was essential to do well, and with this track having the capability to dry quite rapidly, the circuit had the potential to get quicker towards the end of each session. At the same time, the teams had to constantly guard against the risk of conditions getting worse. The teams have gained some information about the crossover point from full wets to intermediates, but they have no information about the crossover from inters to slicks – which might be important in the race tomorrow, where variable conditions are again likely. Even if there is no rain at all, with so little dry running up to now, the teams will be operating with limited data. The wear and degradation for both the intermediate and the full wet tyres are not set to be an issue tomorrow should they be used for the race. Strategy will obviously depend on the weather and for the moment that is wide open: the teams that are able to read the changing circumstances of the race most effectively are going to be the ones that come out on top.”

The Pirelli mystery strategy predictor:

Strategy is going to be very hard to predict and it depends entirely on the weather. Complicating the issue further is the fact that the drivers are all allowed to start on whichever compound they choose (if it is dry) – and they all have a full unused allocation of slicks. If the race remains dry for the entire 71 laps – which seems unlikely – two to three pit stops are theoretically the quickest strategy, but without any data to go on, it’s hard to predict the timing of the stops.