F1 News: Carlos Sainz goes fastest in FP1
Carlos Sainz secured the fastest time in an intense First Practice session, with the altitudes of Mexico providing plenty of storylines.
The top six cars were separated by just two-tenths of a second, with the likes of Fernando Alonso and Lewis Hamilton within touching distance of the Red Bull and Ferrari duo at the front.
The majority of the field completed runs on the soft compound of tyre, allowing for some relatively good comparison and analysis between the different teams.
Power units were tested from the beginning of the session, with Autodromo Hermanos Rodriguez taking several casualties in Free Practice 1.
The rookie drivers seemed worst impacted by the altitudes, as Pietro Fittipaldi, Liam Lawson and Jack Doohan were all limited by mechanical issues in the session.
Guenther Steiner told the Sky F1 team that he expects the team will change Mganussen's engine, perhaps the first confirmation of several power unit penalties this weekend.
AlphaTauri, Alpine and Haas are unlikely to be the only team with issues this weekend in a race which could become a race of attrition throughout the field.
The teams will look to address these vulnerabilities as the weekend continues and the Sunday Grand Prix approaches.