Brazil often provides unpredictable weather, but fortunately for the purpose of this analysis, the drizzle at Interlagos had very little effect the track surface due to the high ambient temperatures.
Once Alonso’s broken McLaren had been cleared, teams sent their drivers out for race stint practice. Since Interlagos has a very short track, all drivers, except Fernando, were able to lap a good tally.
The graph below displays the first 13 race stint lap-times in FP2, with dashed lines indicating that the prime tyre was used. An unbroken line represents the use of the faster option tyre:
Last year, pit-stops occurred just eight or ten laps into the race, and this year won’t be much better. Rosberg seems to be struggling more than most here, with his pace dropping away by two seconds in just 11 laps, but is fastest early on and maybe paying the price for being so.
There are other notable performances disguised in this messy form, but once accumulated and compared to one of the longest runners, Brazil’s Felipe Nasr, it’s clearer to see the comparisons:
Now we can see that while Daniil Kvyat was 0.3s away from his team-mate in hot-lap trim, his car setup and driving combination have a tyre wear advantage over Ricciardo and is gaining on Vettel on the initially quicker tyre for what could be 3rd or 4th place in this practice race. Grosjean on the option by lap 11 is getting swamped by the prime runners as the tyre wear overcomes the performance difference… big time.
Qualifying prediction
To predict qualifying times after FP2, the track evolution and temperature difference should be considered. The teams also run different programmes over the weekend and slowly over the season a trend forms. Perhaps the most obvious one historically is that Williams hold back on Friday and on Saturday you suddenly have to look higher up to see them.
I’ve been recording the percentage decrease in best lap-times from each team in dry sessions for both GP2/3 supported races and non-supported races. Apply these multipliers and we get a rough estimate for this non-supported qualifying as follows:
| Qualifying Rank | Team | Time |
| 1 | Mercedes | 01:11.3 |
| 2 | Williams | 01:11.9 |
| 3 | Ferrari | 01:12.1 |
| 4 | Lotus | 01:12.3 |
| 5 | Force India | 01:12.5 |
| 6 | Red Bull | 01:12.6 |
| 7 | Toro Rosso | 01:12.8 |
| 8 | Sauber | 01:13.1 |
| 9 | McLaren | 01:13.8 |
| 10 | Manor | 01:15.8 |
This applies to a dry track.
Race prediction:
The following optimum races were compiled used Excel. For the top 8 challengers, every lap-time for every possible one or two-stop race is forecasted using historical and FP2 data, with some judgement from myself – that’s an important part.
Just a quick introduction to how lap-times change over a stint: As fuel is used, the car loses weight and goes faster. As the tyre life goes on, the car loses grip and slows down. Combine the two and you get the curve shown in the following graph (which was created before this weekend for educational purposes):
Historical data? You can access every lap-time for modern races on the FIA website, and these times can be interpreted to find relative tyre wear rate estimations (amongst other variables) as shown by this Hamilton/Vettel comparison from Monza:
Right, now for this race, the 2015 Brazilian GP. As previously mentioned, the following races are the quickest possible pit strategies for each driver. I’m restricted to forecasting 2-stop races maximum at the moment, but 2014’s race was 3-stop. The quickest two-stop tyre strategy for each driver is Option-Prime-Prime. The model also assumes cars can overtake by phasing through one-another so there’s no traffic.
Hamilton crosses the finish line in 4445.1 seconds – 42.3 seconds slower than last year’s race due to mainly the kerbs being avoided by the drivers in 2015. He’s had a tyre wear advantage over Nico for the majority of the season and was disappointed to have to pit and reset his stacked advantage in Mexico upon asking. Last year he was also able to extract another second per lap at the end of his stints and quickly closed a 7-second gap after his spin.
Valterri Bottas and possibly Felipe Massa could threaten the Ferrari’s for the podium places. Bottas was just 0.2s from pole in 2014 and Massa picked up a podium albeit 40 seconds off the leader.
Kvyat is the only driver to have a different pit lap strategy on the way of his fastest race. The tyre wear of the Red Bull’s is on par with the Mercedes’ and they should be a close match in the race.
Sadly, Raikkonen doesn’t look to have the pace to challenge for the big points this weekend, but who knows? His tyre wear is considerably more conservative than the Williams’ and traffic could bring them close together.
