The Brazilian Grand Prix ended the 2013 season on a high note, with an exciting race, which was a real journey into the unknown for the drivers and strategists because it was a dry race that came at the end of a wet weekend.
The Pirelli medium and hard compound tyres were selected for the weekend, but the first time they came out of the tyre blankets was as the cars went to the grid.
This made for an interesting race, where teams had to feel their way as the race unfolded, with no data on tyre wear or degradation and a persistent threat of rain, which fell lightly in the final third of the race, but never enough to necessitate a move to intermediate tyres.
Key strategy decisions had a bearing on the outcome.
As the race approached it was dry and the forecast suggested that there was a 40% chance of rain before the start with a 60% chance of rain during the race.
Most teams were planning on doing two stops, with a first stint on the faster medium tyre, but from there it was about guesswork and instinct whether to do two stints on hard or one on each. The simulations suggested that the medium would be around 0.4s per lap faster than the hard, so on paper two stints on that tyre should be faster.
Simulations showed that two stops was five seconds faster than three stops. IN the end only four drivers did three stops, none among the leaders.
As it had rained all weekend, everyone had all new sets of dry tyres for the race.
There were a couple of threats; one was of graining of the tyres, where the rubber shears off the top surface of the tyre, due to the track being clean with no rubber down on the asphalt. This would be a phase, which would probably clear after a few laps.
The other was getting the wrong tyre pressures; too much pressure and the tyres would warm up quickly, then suffer loss of performance, too little tyre pressure and they might never get into the optimum temperature window.
In terms of wear life the feeling was that the medium tyre would be good for 22 laps and the hard 26 laps. In the end, Jenson Button managed 28 laps on the medium and Heikki Kovalainen did 37 laps on the hard.
Early mover advantage
Only two drivers went for the hard tyre off the startline; Jenson Button (14th on the grid) and Esteban Gutierrez (17th).
Button took his best result of the season in Brazil, by using early mover advantage. He didn’t run a particularly long first stint, but he used the hard tyre well, moving to 11th on the opening lap and he had passed cars up to 7th place when he pitted on lap 20, the first of the leading runners to do so. He took a new set of mediums and got ahead of Rosberg, whom he had been following in the opening stint, by pitting two laps earlier.
This put him in clear air for the start of the second stint as he was in a gap of eight seconds behind fifth place Lewis Hamilton, so he was able to run at his ideal pace. After Felipe Massa was given his drive through penalty for cutting across a white line at pit entry, Button moved up to fifth. He was again the first driver to pit for the second time and this took him up to fourth.
McLaren have had a terrible season by their standards, with no podium for the first time since 1980 and qualifying was a disaster for them in Brazil, but they had good pace in the race to end with a season’s best result for Button.
Red Bull make a rare mistake
Sebastian Vettel won the Brazilian Grand Prix, his ninth consecutive win and the 13th of the season, but there were a couple of moments where the result looked like it might be threatened.
Vettel bogged down at the start, from pole position and Nico Rosberg jumped him into Turn 1. Vettel decided to attack him straight away and as they crossed the line at the end of the lap, he pulled alongside and passed him into Turn 1. The Mercedes had been trimmed with more downforce to help with qualifying in the wet conditions the previous day and the Red Bull, with superior grip out of the slow final corner onto the long pit straight, was able to go past. DRS had not been enabled at this point, so the pass was made on pure performance.
Once ahead, Vettel settled into his normal rhythm and planned to space his stops out ideally, with a stop for another set of new mediums on lap 24 and then a set of new hard tyres at the final stop. However the second stop on lap 47 did go according to plan, as Red Bull reacted to an accident involving Lewis Hamilton and Valtteri Bottas, which had left the Williams at the side of the track.
It could have triggered a safety car and with a 70 statistical likelihood of safety cars in Brazil, strategists are always at the ready for the first sign of one. A safety car can be a real game changer and so, to play it safe and cover that possibility off, as the incident was in a pit stop window, Red Bull reacted and brought both drivers in. But it was a very late call and there was confusion in the Red Bull garage, as only three of the four hard tyres were brought out and fitted to the car.
Red Bull had planned a double stop, as Webber had been 10 seconds behind Vettel on the road, so they could have turned him around straight after Vettel, but the hold up for Vettel also compromised Webber as he was forced to queue. Third placed Fernando Alonso also pitted on that lap to cover the safety car possibility and he closed up on the Red Bull pair by 11 seconds as a result of the mix up.
Fernando Alonso’s race was with Mark Webber’s Red Bull and having started ahead, he was passed by the Australian in the opening stint. But he regained the position by stopping two laps earlier. Alonso and Ferrari chose a different strategy at the first stop and opted to get the hard tyre phase out of the way. He managed to find good pace on the hard tyres in the second stint and stayed with Webber, setting himself up for a possible attack in the closing stages on the medium tyres, when Webber would be on hards. In the end Webber was able to stay ahead.
However – and it is a hindsight scenario – if Alonso had not pitted on lap 47 with the Red Bulls, but a lap later (or perhaps earlier), he would have been able to regain the position over Webber as the Australian lost four seconds in his stop, queuing behind Vettel. But Ferrari had the same thought as Red Bull, to cover the safety car possibility.
Tyre Strategies, Brazilian Grand Prix
Vettel: MN MN (24) HN (47)
Webber: MN MN (23) HN (47)
Alonso: MN HN (21) MN (47)
Button: HN MN (20) HN (43)
Rosberg: MN MN (22) HN (44)
Perez: MN MN (19) HN (44)
Massa: MN MN (19) HN (43)
Hulkenberg: MN MN (20) HN (46)
Hamilton: MN MN (21) HN (47)
Ricciardo: MN HN (14) HN (42)
Di Resta: MN MN (20) HN (47)
Gutierrez: HN MN (22) MN (47)
Sutil: MN MN (17) HN (37) MN (54)
Kovalainen: MN MN (15) HN (34)
Vergne: MN HN (10) MN (28) HN (46)
Maldonado: MN MN (23) HN (43)
Bianchi: MN HN (21) HN (47)
Van der Garde: MN MN (24) HN (47) HU (52)
Chilton: MN MN (26) HN (48) MU (66)
RACE HISTORY CHART
Courtesy of Williams F1 Team