TOP SPEED: Hamilton records the highest top speed on the opening day

Having missed the opening session in Mexico, Lewis Hamilton went on to clinch fifth place in the second one-hour session at the Autodromo Hermanos Rodriguez track. F1Technical's senior writer Balazs Szabo analyses the top speeds from the opening day in Mexico.

Mexico City’s Autodromo Hermanos Rodriguez is one of the most unique tracks on the F1 schedule. The Mexican circuit belongs to the group of the relatively short tracks with its length of 4.304 kilometres. It means that driver will need to complete a total of 71 laps to cover the entire race distance.

However, its main peculiarity is its altitude, which at over 2,200 metres above sea level means the air is very rarefied. Therefore the cars generate less downforce, making car set-up and technical management particularly demanding for the teams.

The main straight is over 1.2 kilometres long, on which the cars reach very high top speeds, partly down to the minimal downforce. The track surface is very smooth, and at the start of the weekend does not provide much grip, as it does not get much use.

Therefore it rubbers-in over the three days, which is reflected in improved lap times. Drivers will also need to be careful not to lock up the wheels under braking, due to the tyre surface temperatures dropping quickly down the two long straights. Because of its unusual layout, this is also the track where drivers have to change gear the least.

Mexico’s 2,285-meter altitude means that air density is 20.7% lower than at sea level. Lower air density, and therefore less oxygen, means that everything suffers - although, as ever, some cars suffer more than others.

As a result of this unique location, cars generate a lot less downforce, and cooling is also much less effective. Due to the less air density, the air has less cooling effect which means that both engine and brake cooling tend to be very marginal at Mexico.

The layout and the long start-finish straight would require less loaded rear wing, but the air density makes the Autodromo Hermanos Rodriguez a maximum downforce setup track. However, the altitude means that cranking on Monaco-spec wing levels still gives top speeds higher than Monza.

The opening day of the Mexico City Grand Prix saw Lewis Hamilton record the highest top speed with 352kph while his team-mate Charles Leclerc was 3kph slower across the speed trap.

Based on the highest top speeds, Ferrari, Williams and Mercedes elected to run the lowest downforce setup. In contrast, McLaren, the Racing Bulls and Haas went for a slightly higher downforce level.