What Impact Does High Altitude Have On An F1 Car?

The Autódromo Hermanos Rodríguez is located to the south-east of Mexico City’s centre, with an ambient pressure of just 780hPa – normal sea level is around 1,000hPa, so it’s roughly 20% less. Despite its high altitude, it is one of F1’s flattest tracks with an elevation change from the lowest to highest point of just under 3 metres. This is partly because Mexico City sits in the ‘Valley of Mexico’ on a former lakebed.
 
When it comes to the highest altitudes of other F1 tracks, none come close. In fact, the Mexico City venue is located nearly 1,500m higher than the next circuit on the list, which is Interlagos, measuring in at 800m above sea level.
 
So while the weather and temperatures experienced at the Mexico City Grand Prix aren’t especially different to other race weekends, the atmospheric conditions are unique and provide teams with some rare challenges to tackle.

Altitude impacts everything F1 teams do, whether it’s going for a run around Mexico City or a turbocharger pumping oxygen into the engine of a car. And it’s all related to the amount of air particles and the density of the air at that specific height.
 
The higher you are in the atmosphere, the thinner the air is. This is because air has weight and so the closer you are to sea level, the more the air is being compressed downwards, meaning denser air and more air particles. At 2,285 metres above sea level, there is around 25% less air density compared to at sea level and therefore a quarter less oxygen.
 
When you think about an F1 car, there are many crucial factors that ensure it operates correctly, three of which are: aerodynamics, cooling and the Power Unit. These elements are greatly impacted by the amount of air available to them and therefore, less air means differing performance.
 
High altitude doesn’t directly impact the racing itself, because everyone is impacted in the same way and the long main straight and two DRS zones early in the lap do promote overtaking. However, different cars will be impacted by the effects of the altitude in different ways, some faring better and some faring worse, which can mix up the competitive order in Mexico.

Because of the thin air, the drag of a Formula One car in Mexico City is much lower. There are fewer air particles for the car to move out of the way, so the car cuts through the air quicker and with less disruption. This is why the cars are so fast on the straights in Mexico, with a maximum speed higher than Monza (350 km/h) whilst running wings as big as the ones used in Monaco.
 
However, fewer air particles also have the impact of less downforce being generated, as there is less air pushing the car into the ground. In fact, the downforce loss is around 25% in Mexico because of the altitude. As a result, the highest downforce specification – Monaco level of wing – is used but this is generating the same level of downforce (or even slightly less) as the Monza wing because of the lack of air density.
 
Aero grip is therefore pretty low in Mexico, but you can run a big wing without the penalty of drag, so top speeds are very high.

If we were talking about naturally aspirated engines, the performance difference at a high-altitude track would be much higher, as it relies on oxygen being drawn into the engine to complete the combustion process. This would produce a 25% performance loss, but on the modern-day F1 Power Units this is avoided thanks to the Turbocharger.
 
This is because the Turbo spins at an incredibly high speed to pump more air into the engine – around three times more air, in normal altitude conditions. More air means you can pump in more fuel and therefore generate more power. In Mexico, the Turbo has to work harder to compensate for the lower air density and it does this by spinning at a higher speed, in its attempt to make up some of the performance loss.
 
However, it can’t make all of the performance difference up. Working the Turbo 20% harder just isn’t possible – there isn’t the margin left, because they are designed and built for normal race conditions, not the unique ambient pressure of the Autódromo Hermanos Rodríguez. So, there is still a sizeable reduction in Power Unit output, but the lower drag helps make up for that and propel the cars to these incredible maximum speeds on the Mexico City track’s long main straight.
 
There is also less harvesting from the MGU-H in Mexico because less air into the engine means less power and less exhaust gasses for the MGU-H to recover and turn into useful energy. Some manufacturers will fare better than others depending on the size of their Turbo and the layout of their Power Unit system.

The way F1 cooling works is the cooler air particles pass through the cooling intakes, picking up the heat from the components before being dispersed out of the back of the car as hot air. A higher altitude means less air is passed through the radiators, air intakes and ducts which results in less cooling, meaning the various elements of the car such as the Power Unit and brakes run hotter or require much larger ducts to get things sufficiently cooled down.
 
Obviously, teams try and open up the car’s cooling outlets as much as they can, increasing the size of the air intakes and ducts to bring more air particles in, but this also reduces the aerodynamic performance and increases the drag of the car, so a balance has to be found between the two.
 
Cooling the car appropriately is probably the biggest challenge in Mexico. For the Power Unit, the lack of mass flow of air limits the cooling potential, which requires careful management to ensure reliability. And overheating brakes can lead to accelerated wear or glazing (where the surface is burnt off, turns shiny and therefore drops friction). Furthermore, the turbo spinning at higher speeds causes additional mechanical strain on the turbine and compressor elements. These are all delicate issues that teams have to consider, monitor and react to, which all add to the excitement and challenge of the Mexico City Grand Prix.

The highest altitude track in Formula 1 is the Autódromo Hermanos Rodríguez, located in Mexico City, Mexico. The circuit sits at an impressive elevation of 2,285 meters (7,500 feet) above sea level, making it the highest track on the current F1 calendar.

This is over 1,000 meters higher than the next highest circuit, the Autódromo José Carlos Pace (Interlagos) in São Paulo, Brazil, which is situated at an altitude of approximately 800 meters (2,625 feet).

F1 cars are generally faster at the Autódromo Hermanos Rodríguez in Mexico City, despite the high altitude, due to a combination of factors related to the track layout and the unique atmospheric conditions.

Long straights: The Mexico City circuit features two exceptionally long straights, the main straight and the back straight, which allow the cars to reach incredibly high speeds. The reduced air density at the high altitude means there is less aerodynamic drag acting on the cars, enabling them to achieve higher top speeds compared to sea-level circuits.

High-speed corners: The track layout also includes several fast, sweeping corners that favor a low-downforce setup. With less air density, the cars generate less downforce, which can be beneficial in these high-speed sections as it reduces the overall drag on the car.

Turbocharger performance: The turbochargers on the F1 power units are designed to compress the incoming air to maintain optimal combustion and power output. At high altitudes, the turbochargers can spin faster due to the reduced air density, allowing them to compensate for some of the power loss associated with the thinner air. This helps the cars maintain a higher level of performance than would otherwise be possible.

Cooling efficiency: The reduced air density at high altitudes also affects the cooling efficiency of the car’s various systems, such as the engine, brakes, and electronics. However, the lower temperatures experienced at the Mexico City circuit in late October, when the race is typically held, help to mitigate some of these cooling challenges.

Altitude has a significant impact on the performance of Formula 1 cars, with higher altitudes leading to reduced engine output and changes in aerodynamic performance. The primary reason for this is the decreased air density at higher elevations.

As altitude increases, the air becomes thinner, meaning there are fewer oxygen molecules available for the car’s internal combustion engine. This reduction in oxygen results in a decrease in engine power output. On average, engine output is reduced by approximately 1% for every 100 meters increase in altitude above sea level.

To put this into perspective, the Autódromo Hermanos Rodríguez in Mexico City, which sits at an altitude of 2,240 meters (7,349 feet), sees a significant reduction in engine performance compared to sea-level circuits like the Yas Marina Circuit in Abu Dhabi. At the Mexico City circuit, F1 engines are estimated to produce around 22% less power than they would at the Abu Dhabi track.

In addition to the impact on engine performance, altitude also affects the aerodynamics of an F1 car. The thinner air at higher altitudes results in less aerodynamic drag, which can lead to higher top speeds on the straights. However, this comes at the expense of reduced downforce, which is crucial for cornering performance and overall lap times.

To compensate for the effects of altitude, F1 teams must make significant adjustments to their car setups. This includes changes to the aerodynamic package, such as running higher downforce configurations to compensate for the loss of downforce due to the thinner air. Teams also need to adjust the engine mapping and fuel flow rates to optimize performance for the specific altitude conditions.