Welcome to The Briefing, where we’ll be answering the key on-track questions ahead of the Miami Grand Prix.

Each week, powered by Google Cloud, we’ll be speaking to one of our trackside experts to walk you through the biggest talking points and provide you with a simplified guide of what you’ll need to know to jump straight into the action. This week, we spoke to Will Joseph. 

One year on from McLaren’s first victory in three years, achieved at the 2024 Miami Grand Prix, we return to the circuit in title-chasing form. Whereas last year, everyone was asking about the team’s impending upgrade, the questions in 2025 are around the softer tyre choices available to us and how we’ll setup to tackle the circuit’s long full-throttle sections. We’ll also analyse how we plan to attack this weekend’s Sprint and what our Grand Prix strategy options are.

One year ago, the Miami Grand Prix was a turning point, with a significant upgrade fitted to the MCL38. Do we have something similar for the MCL39 this year?

Sadly, not! I wish I could tell you that we had a similar-sized upgrade to last year, but no, there is nothing significantly new for Miami. It’s a Sprint event, and last year, we took that risk, as we have done a few times, to bring big upgrade packages to the Sprints because with more points on offer, it’s justified. This year, though, there was no big upgrade, and the weekend will be more about optimising what we have rather than trying to understand something new.

Long, full-throttle sections in Jeddah last time out, long full-throttle sections here: does that mean the set-up will be similar?

Similar-ish. Downforce-wise, we’ll have the same rear wing as in Saudi. On paper, running slightly more wing would be beneficial, but that assumes you’re racing by yourself, targeting lap-time. As soon as you bring other cars into the mix, we’ll want to take off a bit of downforce to make sure we’re competitive at end-of-straight.

The major difference between the two tracks is that Jeddah is very high-speed. Miami, if you ignore Turn 3 and Turn 7, is actually very low-speed. We will want to keep some compliance in the car for the very low-speed corners, to run over the kerbs and open the trajectory, and the way that’s done is to bring the roll-stiffness down a lot from Jeddah, which was a very high roll-stiffness circuit.

It is, however, a very smooth track at the Miami International Autodrome, which means we can keep the heave stiffness quite high. This is attractive because we will still want to generate as much load as possible in low-speed, and the way to do that is to run stiff and low.

We’re in the middle of four races where Pirelli are going a step softer with the tyre allocation than last year. Despite this change, Jeddah remained a one-stop strategy. Is Miami going to be different?

There is a strong possibility that it won’t! It still looks like a one-stop. A different one-stop - a slightly trickier one-stop, but still a one-stop. Of course, we won’t know for certain until we run on the track, but the pre-event models still suggest the one-stop race with the Medium and Hard compounds is the quickest.

Does having a different tyre allocation for a Sprint weekend cause a few headaches?

Understanding the tyres remains the priority. At a Sprint weekend, your first run pretty much defines tyre usage for the rest of the weekend, so making the initial decision on which tyre to use in the practice session is very important.

You try to learn what you can in practice, then are straight into Sprint Quali, where tyre usage is prescribed, and then the Sprint itself is almost the first time you get to do a proper long run and start to learn and understand what might impact your plans for Sunday. So, coming to an event like this with different tyres, you’ve learned less by the point at which you have to make decisions, but you learn quite a lot as the weekend progresses.

It is feasible that somebody might choose to use a set of Hard tyres in the Sprint?

Yes! Certainly, on paper, the Hard tyre looks like the quickest tyre for the Sprint. The question will be are you willing to risk not having two sets for the race? If it is a one-stop race, then you don’t need two sets – but it is the robust tyre, and it’s always useful to have both sets if there’s a poorly-timed Safety Car or other uncontrollables.

So, will people run it in the Sprint? Potentially. You know it'll be robust. On the other hand, it will have slightly worse start performance, which teams are always quite nervous about in the Sprint, because history suggests that anything you lose at the beginning, you’re very unlikely to recover.

I think perhaps a more interesting question is: would anyone be brave enough to fit the Soft? Again, on paper, it seems unlikely – but teams sometimes do these things.

Is the C4 Medium compound the critical one to research?

Yes. You’ll use the Soft tyre when you have to – which is in SQ3 and Qualifying. The Hard is the preferred race tyre, and what happens with the Medium through the event largely determines how you approach the race.

You can look at last year’s race, which was a Medium>Hard, C3-C2, and we barely saw the Soft – which is this year’s Medium. We know it’s a better tyre this year, but the questions are: how much better, and what does that mean? Zhou Guanyu did a decent-length stint on it last year, and this is why a one-stop strategy still looks acceptable.

I think, in general, there’s been a small step improvement in all the tyres for 2025. The C2 compound is the one that’s moved around most but all of the tyres seem to have better graining resistance, which was the intent – but the reality is we still have a lot to learn about them.

Are you a fan of the Sprint weekend format?

I am and I'm not! On the one hand, it’s nice to do something different. Personal opinion: I think it demonstrates that for good racing, you don’t necessarily need to have three practice sessions. I like the fact it rewards preparation more: the better you come out of the starting blocks, the better weekend you seem to have – and I like that.

On the other hand, it’s a lot more work and a much more stressful weekend! From the moment the car leaves the garage for practice, every decision has a raised level of intensity. I like that because it’s more competitive, but it’s a harder weekend on an engineering and a personal level.

Does the Sprint format alter the interaction between the trackside team and everyone supporting back at the MTC?

In the current era, we’re relying of the factory more than ever before. We are always time-limited and, even at a normal weekend but especially at a Sprint, there is only so many things we as individuals can do, and therefore the more the factory can assist us in making decisions, the better.

Think about something like setting ride heights – something that’s become even more important recently with the disqualifications that the FIA have made on Sprint weekends. It's a performance opportunity and a legality risk and therefore it requires a level of workload that, if put on the race engineer at the track, they'd probably get nothing else done. So, we share the workload and have other people help us make those decisions. It's not to say they make the decisions for us, more that the factory can provide a lot of information, and that helps us make decisions in the short amount of time available.

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