Analysis of key indicators and trends from United States Grand Prix

Not by any means a classic race, the 2013 US Grand Prix, but an interesting one from a number of perspectives. The strategy was quite clearly defined by the conservative tyre choice made by Pirelli. There was little variation across the field with only Jean Eric Vergne starting the race on the hard tyre, while everyone else went with mediums and made one scheduled stop.

But there are some interesting talking points and indicators of future trends, which are worth considering from this race.

Pre-Race Strategy Expectations

Pirelli once again announced the two hardest tyres in the range for the US Grand Prix, a very conservative choice. Why did they do this? Partly because it’s America and they didn’t want to take any chances, given F1’s history in the country and partly because it served as a useful and timely reminder to the F1 community and fans of what F1 racing is like when the tyres are super durable, with little or no degradation. It can make for some dull racing.

It was almost a reminder of what it as like in the final year of Bridgestone tyres, where a driver could stop early in the race and drive to the finish on one set of tyres. It takes away much of the strategic dimension to the racing. It gives the teams and rule makers something to ponder as they prepare for the 2014 season with all new tyres.

Before arriving at Austin, some teams’ simulations were showing that two stops might be the best solution, but after Friday practice it was clear that the tyre degradation was very low and one stop would be the plan, as it was here last year. However the variable was provided by the temperature, which was hard to predict, with early morning ambient temperatures as low as 5 degrees and highs of 27 in the afternoon! This meant track temperature variations of 20 degrees from low to high. It’s highly unusual to encounter that at a Formula 1 Grand Prix venue.

There was a safety car early in the race, while debris was cleared from Adrian Sutil’s accident. This extended the first stint in most cases and made it an even safer one stop race.

Grosjean beats a Red Bull

One of the standout performances was Lotus’ Romain Grosjean, who finished second ahead of Red Bull’s Mark Webber. They lined up in the grid in the opposite order, so Grosjean did well to beat the Australian.

His result was set up by a strong start, from the clean side of the grid, to jump Webber into Turn 1. The Lotus was quicker than Webber’s Red Bull (but not Vettel’s) on the medium tyre in the opening stint and Grosjean was able to lap in the 1m 44s consistently, dropping into the 1m 43s towards the end of the stint.

The threat strategically to Grosjean was Webber undercutting him, but the Frenchman was able to maintain the crucial five second gap over the Australian which prevents an undercut. So Lotus were happy to let Webber pit first on lap 28 and then they pitted Grosjean a lap later to cover him.

There was slight concern about warm up on the harder compound tyre in the initial phase and also that Red Bull would be faster on it. By pitting first Webber cut the gap to just one second and pressured Grosjean for the remainder of the race.

The Red Bull was faster in the first sector of the lap, but the Lotus was faster in the sequence of corners leading to the all important back straight, so was able to hold Webber off. The closest Webber came to him was 0.7 secs behind, so he was never able to mount a sustained passing move.

Bearing in mind the characteristics of the Lotus car in the last couple of seasons, which has been gentle on tyres and competitive on the softer compounds and in warmer temperatures it was impressive that the car was so competitive on the harder compounds in Austin.

Record pit stop for Red Bull

Red Bull performed the fastest ever pit stop during the US Grand Prix, on Mark Webber’s stop on lap 28. The car was in the pit lane for 23.537secs, with a stationary time of time of just 1.923 secs. This is not an official record because stationary times are not officlally measured by the FIA, only the pit lane time is measured by them and they do not keep a league table of stops.

Great result for Bottas and Williams

Valtteri Bottas and Williams were on great form in Austin, bagging four points for eighth place - Bottas’ first points in F1. They were timely, as it takes the pressure off Williams going into the final race in Brazil. With only one point on the board, as they had before Austin, they were potentially vulnerable to a freak result for Marussia or Caterham which could plunge them out of the prize money placings. Now with five points on the board they are probably immune to that.

Bottas’ result was set up by qualifying, where he made it into Q3 for only the second time this year. He made a small mistake on his final run. Had he improved from Q2 to Q3 as his peers did, he would have started fifth on eth grid instead of eighth.

The secret behind the Williams’ performance in Austin was two fold: new technical director Pat Symonds had decreed that the team should abandon the troublesome Coanda exhaust system, which had not worked on the car all year. This would normally make a car harder on its tyres, so taking it off earlier in the season would not probably have helped in a race where the soft compounds were being used.

But for Austin – and probably for Brazil next weekend too, where the same tyres will be used – it worked well. The Williams worked on the medium and hard tyres and it was further helped by the cooler track conditions.

So a smart strategic decision by Symonds on the specification of the car played to the conditions and the tyres provided and gave them the result.

The cooler temperature characteristic is not new; we have seen Williams looking quick in Free Practice 1 and 3 sessions this year, which are held in the morning when the track temperatures are cooler. Their pace has then eluded them in qualifying and the race as the temperature has come up.

The UBS Strategy Report is prepared by JA on F1, with input and data from several F1 teams, from JA on F1 technical adviser Mark Gillan and from Pirelli.

Tyre Strategies, United States Grand Prix

Vettel MU HN (27)

Grosjean MU (HN 29)

Webber MU HN (29)

Hamilton MU HN (25)

Alonso MU HN (26)

Hulkenberg MU HN (27)

Perez MU HN (22)

Bottas MU HN (23)

Rosberg MU HN (22)

Button MU HN (20)

Ricciardo MN HN (22)

Vergne HN MN (27)

Massa MN HN (21)

Gutierrez MU HN (1) MU (36)

Kovalainen MU HN (17) MU (31)

Di Resta MU HN (22) MU (49)

Maldonado MN HN (8)

Bianchi MN HN (21)

Van der Garde MN HN (21)

Pic MN HN (20)

Chilton MN HN (26)

M = Medium; H=hard; N=New; U= Used

Race History Chart,

Kindly provided by Williams F1 Team

The vertical axis is the time difference behind a ghost car, which is setting the average lap time of the winner every lap. The graph is useful for showing the relative performances on each stint of the cars and the gaps between them.