• INSIGHT: Mexican Grand Prix: Your Questions Answered

Andrew Shovlin answers your Mexican GP queries!

Mathijs Elgersma (@elgersmamathijs) asked us on Instagram:

- What was the expected strategy for the race?

Andrew Shovlin: "Well, we obviously do work on Friday, we look at how the tyres behave, we knew the UltraSoft was going to be a tricky tyre, not as tricky as the HyperSoft, that was even more difficult to manage.

"But, the SuperSoft on Friday had performed well, it didn't have the graining that we saw on the other compounds and the degradation was low.

"So, going into the race, we thought we'd just be able to make a one-stop work. As it happened on Sunday, we had higher degradation, the track conditions were actually making it tougher on the tyres, despite being a bit cooler.

"And that higher degradation was what triggered us to change strategy and take the additional stops."

Margaret Mazan queried on Facebook:

- Why was the tyre degradation so high? Also, how was it you only had used sets to change onto?

AS: "Well, the first question, it was because we were seeing graining, which is a mechanism when the surface of the tyre gets damaged and you start to get waves appearing in the rubber, and that results in less grip.

"And this is what was happening on the front tyres, you could probably see that from the onboard cameras.

"Now, we weren't the only ones suffering from that, but we were definitely suffering from it worse than Ferrari and Red Bull. And it just causes the car to understeer, you get this loss of grip and it is very difficult for the drivers to maintain the pace.

"The second part of the question, why did we only have used sets. Well, sometimes if we don't want to use a harder set of tyres in Qualifying, we'll leave it for the race and it is there as a new set.

"However, the selection here was at the very soft end, we were able to use our UltraSoft tyres during Qualifying, so we had put laps on those tyres.

"However, the SuperSoft tyres were new for the race. It was just that once we had used that SuperSoft, all of the tyres we had to choose from were either used UltraSoft or used HyperSoft."

Lyndsey Parker (@nailpixi01) sent us this tweet:

- Was it purely the altitude of the Mexican track that made the race tough on your guys or was it all just down to the tyres Pirelli chose?

AS: "Well, there are two elements to that. One is the altitude is very tough on the cars, the air is very thin, you need to open up the car to get the cooling but more importantly the downforce is reduced because the air is a lot less dense.

"And that means that the car slides around a bit more, it is going a lot faster in a straight line and when you are braking, you haven't got as much downforce and grip.

"So, that is one factor. In terms of the tyre selection, yes it was an aggressive choice, we were seeing people struggling on both the HyperSoft and the UltraSoft tyres.

"But, from our point of view as a team, we need to make sure we are doing as good a job as our close competition, that's Red Bull and that's Ferrari. And in the race, you could see they were able to manage the tyres a bit better.

"So, we are doing a lot of work back here this week understanding that. We have made some progress on that problem and hopefully we can avoid a repeat of that particular issue."

Kevin Joly (@vinke_off) left us this comment on Instagram:

- Why did you put Valtteri on a three-stop?

AS: "You'd seen on the UltraSoft tyre, the one that Valtteri was running actually on his third stint was actually degrading quite badly and this wasn't a new tyre.

"This was a tyre he'd run at the start of Qualifying. We'd also used that tyre for some laps to the grid. When he started to suffer the degradation, it was causing a drop in lap time.

"Now, at that point of the race, there was no one behind Valtteri. We had Hulkenberg, who was almost a lap down to us, so it was actually possible for Valtteri to come in and take the HyperSoft tyre towards the end.

"Which just gave him a bit more grip, it was a bit easy to handle the car. But there was no loss of position.

"The problem is the HyperSoft also had a lot of degradation, so we had to wait until we were confident that going to that tyre would give us enough rubber to get to the end of the race from that point."

Mullins (@1mullins1) asked on Instagram:

- Do you think limiting the amount of practice is a good way of making the race more interesting?

AS: "Well, actually we had more or less complete practice sessions in Mexico. If you look back to Austin, we didn't.

"We lost the Friday running with the rain, so very limited practice there for the drivers and very limited time for the engineers to get the cars set up.

"And Austin was a good race, it was interesting because people don't know quite how far you can take the tyres so definitely on one side, it will lead to less predictable racing, if you give the teams less time to understand how far the tyres can go, less time to fine-tune their set-up.

"But generally, teams will try and find ways around this if we restrict it. They will look at what they can do in simulation, what they can do using models.

"But, certainly in Austin it probably led to a more interesting race than we may have otherwise had."

Kendal Slater (@kendaljslater_) sent us this on Instagram:

- Is there a particular aero package you could develop specifically for the high altitude of Mexico? Or does mechanical grip have more of an emphasis?

AS: "The answer to the first part is yes you could. The thin air means that you generate less downforce, less drag. And because of that, we are running the wings that we would run round Monaco and Singapore, but we are actually only generating the drag and downforce that we would have at a track like Monza, where you run much, much smaller wings.

"So, if we had wings that generated more drag and downforce, we would run them in Mexico, but the fact is it is a one-off race. You have got to be a bit careful how much time you spend developing for these one-off races because it detracts from your core performance at the other circuits.

"Now, part two of that question was about mechanical grip. Well, it is a low-speed circuit, all the corners are at low speeds despite the long straight and then mechanical grip is important. So, it's one where you have to try and optimise the car to generate as much grip as you can and in this instance, it was how well you were looking after the tyres that was the big factor there.

"So, the degradation in the race is because the surface of the tyre is being damaged and that means there is less of the tyre in contact with the road, there is a drop in grip and that is what leads to the degradation in terms of lap time."

Martin Bashforth @MartinBashforth - Twitter

- At what point do you switch development to 2019? Has it already been done, or do you wait till both titles are sealed?

AS: "The first point is it isn't really a switch, you ramp down the development on the 2018 car and you start ramping up the development on the 2019 car.

"And by now, the vast majority of everyone's teams are going to be focused on next year's car. But some of those items, you have got to start very early.

"Things like the gearbox, the chassis, suspension positions. That's all work that happens quite early in the season and by the summer break, historically most teams will have had the majority of their resource focused on the following year.

"But, even at the last two races, we have had developments on our car, we've seen Red Bull, Ferrari looking at developments to the floor.

"That might be with a bit of an eye to next year, but it clearly shows that they are still putting some resource on those current cars."