When you’re gasping for breath after running up a flight of stairs in the Formula 1 paddock at the Autódromo Hermanos Rodríguez, it’s easy to question your fitness. But in reality, the lack of oxygen in the air at this weekend’s Mexico City Grand Prix will be the culprit — and everyone is affected.

 

 

At 2,240 metres (7,350 feet) above sea level, Mexico City is one of the highest capital cities in the world. Its thin atmosphere, with about 25 per cent less air density (which equates to a quarter less oxygen), presents a significant challenge. And not just for our drivers, Esteban Ocon and Pierre Gasly, but for Alpine’s engineers too. As we descend on Mexico’s F1 track this weekend, the task will be preparing for the impact the high elevation will have on the cars, power units, brakes and aerodynamics.

 

 

In the days of naturally-aspirated engines, altitude had an even greater affect than it does with the current turbocharged 1.6-litre power units. But to compensate for the reduced air density, the turbochargers have to work much harder, spinning at higher speeds to force more air into the engine. The overall reduced performance results in fewer exhaust gases which also means the MGU-H, which harvests energy, has less to recover, further reducing efficiency.

 

 

Cooling is another crucial factor at Mexico City’s high altitude. The thinner air affects the car’s ability to cool both the power unit and gearbox, which is why every team will revise their bodywork with special cooling vents or louvres to manage airflow, especially around the radiator sidepods and engine cover. While this helps keep temperatures in check, these extra cooling features can create drag, compromising aerodynamic performance.

 

 

The brakes are another component that need additional cooling, especially with the long straights at the 4.3km (2.6-mile) Mexican circuit. The run down from pole position to Turn 1 is the longest of the season, at 811 metres, and braking from some of the highest speeds of the year, into a series of slow corners will mean it’s vital brakes are kept within their optimal temperature range.

 

 

One of the most curious aspects of racing at altitude is how it affects downforce setup. Typically, the Autódromo Hermanos Rodríguez would require a low to medium downforce configuration if it were located at sea level. However, the thinner air means that wings are less effective in pushing the car onto the track surface. As a result, teams will run maximum downforce levels with large front and rear rear wings cranked up — settings more commonly seen at tight street circuits like Monaco.

 

 

Additionally, the lower drag caused by the rarefied atmosphere allows for incredible straight-line speeds, as demonstrated in 2016 when a top speed of 372.5kph (231.4mph) was recorded in the pit straight speed trap. With all the variables to balance, it results in the Mexico City Grand Prix being a unique engineering challenge. It’s enough to take your breath away…