Alonso Says Aston Martin Underestimated Mexico's 'Moment of Truth' Test

Fernando Alonso believes Aston Martin and Honda underestimated their "moment of truth" test in Mexico City after power-unit failures wrecked the team's weekend at the Autodromo Hermanos Rodriguez. The two-time world champion had felt his car could have challenged for a strong qualifying position, but he was told to stop after just one flying lap in qualifying because of a water pressure issue. New parts were fitted for the race, yet both Alonso and team-mate Lance Stroll retired after only five laps, with the team citing abnormal pressure levels in the power-unit systems. The altitude of Mexico City, at 2,285 metres above sea level, is one of the toughest tests on the calendar, with air density around 20 per cent lower than at sea level, forcing the turbos to work far harder. That challenge has only grown with the removal of the MGU-H from the 2026 power units, which previously helped eliminate turbo lag. Alonso was blunt in his assessment, suggesting the team had not done enough to meet a challenge it knew was coming. For a team still trying to build momentum, a double retirement so early in a race is a painful setback, and the focus now turns to understanding exactly what went wrong before the championship moves on to Brazil.