Mark Hughes: How Mexico’s quirks changed F1’s major fight

Mexico City’s extreme altitude always contributes to some interesting performance dynamics among cars. When the air is 25% less dense than at sea level, the difference between a Formula 1 car that normally hauled and one that did not is much less than normal. For the same reason, a reduction in downforce means that each additional increment produced is worth the extra.

This goes a long way to explain why the high-downforce but draggy Mercedes – a car that was about 0.6 seconds off the pace in Austin last week – was bang on pace here and only a better final lap by Max Verstappen put the raid on. Secured a bull pole from George Russell’s Mercedes. Here it was the Ferrari that was in the middle of nowhere, fifth and seventh and 0.6s off speed.

For reasons largely unrelated to aerodynamics, altitude is also why Ferrari is not at its best here, as suggested by Carlos Sainz: “We lose a lot of performance in high altitudes,” he added, “But I think it is one. Outright. The height of this engine is not what we want it to be. We knew we had to make some compromises before we got here.”

He’s referring to Ferrari’s unique intake and turbo configuration. With super-long inlet tracts (which increase the turbulence and flammability of the inlet charge), a less-revving MGU-H and a smaller turbo (which takes less electrical energy than others to spin quickly), This usually has a significant acceleration advantage from corners, even if at the cost of earlier clipping at the end of the straights. With a 25% reduction in air density in Mexico, this advantage disappears. Ideally a large turbo is required.

The Ferrari’s front-loaded power delivery (at normal height) is also part of its handling strength in low-speed corners. Take a look at any of this year’s Charles Leclerc telemetry and it can be seen how much he overlaps the throttle and brakes in slow corners, using it to spool up the turbo. It’s an incredibly complex style and Sainz has come to emulate through the seasons. This has an impact on the car’s set-up, which requires a strong front end.

So are the basic characteristics of the three top cars – and how their strengths and weaknesses are replaced by the unique challenges of Mexico City. The Red Bull is a great all-round combination of low drag, good power and consistent downforce at all ride heights. The Mercedes is draggy, but has great downforce if it can be driven low enough – but it’s hard to deal with at slow speeds due to the compromises made by its rear suspension in combination with low- and high-speed corner performance. The Ferrari has tremendous downforce, is somewhere between a Red Bull and a Mercedes in drag, and generally has a low-speed acceleration advantage. but not here.

Now factor-in the special circumstances of the day. Teams were unusually dependent on FP2 because of Friday’s 2023 Pirelli test. This morning the track temperature was around 39C. But it only took a little sun to send the track temperature rising to this altitude and it was up to 50C by the time qualifying began. As Russell pointed out, this not only reduces overall grip, “but it also changes the range from front to rear of the car”.

In FP3 Red Bull was struggling for a front end and Mercedes were in a very happy place, with Russell and Hamilton clearing 0.4s from Verstappen and 0.7s from Ferrari. But around a track 11C hotter, the balance limit switches to the rear as the rear rubber heats up quickly. It was perfect to bring Red Bull to its sweet spot, less good for Mercedes and worse for an already overpriced Ferrari.

But even so, Mercedes was still perfectly competitive with Red Bull, essentially faster in the corners, slower on the straights and equalizing the laps. Sergio Pérez and Hamilton both suffered power unit derivation problems (another danger of this height) and the Ferraris were struggling, so the fight for pole went down to Verstappen versus Russell, especially after Hamilton made his way to track boundaries. The first Q3 time was removed.

“Argh,” Russell shouted in desperation as his last lap turned away from him. “Was there to take the pole.” He lived up to his first run time, which was 0.304s slower than Verstappen’s last flier.

Fresh out of the car, Russell was convinced he would lose laps with an oversteer moment between Turns 4 and 5 and his subsequent run-wide moment as he entered the stadium was simply an attempt to make up for lost time from the earlier incident. In. But a glance at each lap’s GPS reveals that the quick oversteer snap cost him almost nothing and Mercedes’ large downforce through the first half of the aces (7-8-9) put Russell ahead with the red. Bull’s more direct motion then pulls Verstappen back level on the approach to the stadium section. There was nothing in it between them as Russell then took too much speed at Turn 10 and ran on his way to the exit.

It could also have been Verstappen’s pole without Russell’s fault, as Red Bull was consistently fastest through the last sector. But it was no mistake for Russell to realize that the pole had become possible.

In the end, a fine all-round combination of car characteristics and driving secured Verstappen the pole.