Thin air and thick beads of sweat on your brow – these are typical conditions for the drivers and co-drivers during Rally Mexico, as no other rally in the WRC calendar will take them to higher altitudes. The rally vehicles and their occupants have to contend with altitudes of more than 2,700 metres. The highest special stage of the rally goes by the appealing name of ‘El Chocolate’ – but it’s hardly a treat for the rally entrants, as both man and machine suffer from a shortage of oxygen at this altitude, 2,739 metres. Up here, the power output of the World Rally Cars’ turbocharged engines is reduced by around 15 per cent. This is hardly surprising, considering that this altitude equates to the Eiffel Tower (324 metres) stacked on top of itself more than eight times over – and if you’ve ever been to the top of Paris’s famous landmark, you’ll appreciate just how dizzying it is up there. You would also have to stack the world’s tallest building, the 828-metre Burj Khalifa in Dubai, more than three times in order to match the altitude of the ‘El Chocolate’ special stage.