F1 testing analysis: Thursday race simulations

Posted on February 24, 2012


In order to refine the analysis from yesterday, I simulated the Spanish Grand Prix from 2011, in order to provide a better idea of the fuel effect penalty and the expected tyre degradation. Turns out the guesses weren’t too bad, but the fuel effect is a little larger than I had used, and this has helped the understanding of the Hamilton race simulation, as the evidence strengthens that the car is fuelled between some of the stints.

I have added the data from the race simulations of Webber, Button and Schumacher from the Thursday of the test, again with fictional in/out laps to be consistent. The ‘race history chart’ is below:

The initial reading would (of course) be that Red Bull is well ahead, and that Mercedes is somewhere near McLaren. As we know, understanding testing data is notoriously difficult, and this is almost certainly not an accurate picture. So what can we see?

The first thing to note is the tyre degradation in each stint – the greater the downward curve, the higher the degradation. Vettel is clearly showing less degradation than anyone else – this is most likely to be due to his using tyres with fewer testing kilometres on them (closer to a real race simulation) than the other cars. The degradation here is not consistent (except in Vettel’s case) with the Barcelona race last year, so even allowing for the lower temperatures, I think that the tyre age is a significant factor. Also worth noting (as pointed out yesterday) is that the McLaren pace falls away almost stint-by-stint.

This suggests we should have a closer look at the stint-by-stint pace for each car. If we consider the pace of Vettel’s first stint as a baseline, we can compare the pace of each stint (discounting the large tyre degradation phases) correcting for the fuel load using the intelligentF1 model, and allowing for nominal degradation. The pace differences between stints are due to tyres, possibly engine maps, and in the case of the McLarens, probably fuel as well. I have tabulated the pace to show what is going on:

Driver              Stint        1              2            3            4            5         6

Vettel                               +0.0    +0.0   +0.6     +1.2    +0.0   +0.0

Hamilton                         +0.0    -0.2    +1.0     +2.2    +2.2

Webber                            +0.0    +0.0   +0.6     +0.6   +1.2

Button                               +1.0    +1.6   +1.6      +2.3    +3.3

Schumacher                   +1.0    +0.7  +1.8      +1.8

Vettel’s ‘race’ is by far the most consistent and easy to read. It looks like he has used four sets of similar age/type of tyre with two different compounds (or tyre ages or engine maps) in the middle laps. As we know he did not refuel, it is easy to make sense of this trace. What we do not know is how close the car setup is to an absolute pace. I would guess there is quite a lot more to come – although it is worth noting that the overall ‘race’ time is pretty close to last years Grand Prix.

Webber’s race is similar, but he makes one fewer stop. The stint speeds are very consistent with Vettel. Schumacher has also a consistent pace which would suggest that he is also running without refuelling. The second half of his race also seems to be on different tyres, although it is possible that this could be a refuel. We can’t say if the Mercedes is really a second down on the Red Bull due to the number of variables in play, but this would count as a small step forward from where they were last year.

The data from the McLarens is hardest to fathom, especially as the pace gaps between stints seem to be about 0.6s for the other cars (slightly bigger for Mercedes – but that could be anything) and we see second gaps for both Hamilton and Button. Hamilton drops a second in pace from stint 2 to stint 3, and again from stint 3 to stint 4. Interestingly, as he is running stints of the order of 10 laps, this could mean that the fuel is replaced to approximately the load at the beginning of the stint. So, in effect, stints 3 and 4 become repeats of stint 2 (back-to back comparisons?). This is not conclusive, but it does add weight to the argument that the McLarens added fuel during the ‘race’. For Button, this would give us stint 5 as a back-to-back on stint 4. What it doesn’t tell us is why Button is a second slower than Hamilton – there is no evidence even to tentatively speculate. For conspiracy theorists, maybe Hamilton was running light and McLaren isn’t that quick. Maybe, but the positive noises coming from the Woking boys would suggest not.

So what do we have? A good idea of a baseline pace from the Red Bull. An inkling that the McLaren looks pretty close on pace, and a reasonably competitive ‘race’ from Mercedes. And more data to come from Friday, where many of the teams ran long.