Aston Martin faced a challenging weekend at the 2026 Mexico City Grand Prix, with both Fernando Alonso and Lance Stroll retiring after just five laps due to cooling problems. The issues were linked to the MGU-K and ERS cooling systems on their Honda power units, which struggled under the high-altitude conditions of the circuit.
During qualifying, Alonso already experienced an MGU-K cooling issue that limited his running in the first segment. On race day, the cooling difficulties worsened for both drivers, forcing them to reduce power early in the race. Alonso made a pit stop in an attempt to lower temperatures but eventually retired, while Stroll continued briefly before being instructed to stop on track.
Honda’s Trackside General Manager, Shintaro Orihara, explained that the ERS cooling circuit was under significant stress due to the unique conditions caused by Mexico City's altitude, a factor that had been underestimated. Aston Martin’s Chief Trackside Officer, Mike Krack, acknowledged the positives from Alonso’s pace in practice but confirmed that cooling and altitude effects presented major challenges throughout the weekend.
Alonso expressed his frustration with the situation but remained hopeful about the future, mentioning a completely new engine project planned for the next season. The team views the weekend as a learning experience to improve reliability and performance under challenging conditions. Both Aston Martin and Honda are focusing on addressing these cooling and power unit issues as they prepare for upcoming races.
The high altitude of Mexico City, which affects air density and cooling efficiency, proved to be a significant factor in the difficulties faced by the Aston Martin cars. This environment placed extra stress on the energy recovery systems, which are critical for power delivery and efficiency in modern Formula 1® cars.
Despite the setbacks, the team’s assessment highlighted some encouraging signs from Alonso’s practice pace, suggesting that there are areas of potential to build upon. However, the cooling problems clearly overshadowed their race performance, leading to an early end for both drivers.
This episode underlines the complex challenges teams face when adapting their power units and cooling systems to different circuits and environmental conditions. Aston Martin and Honda’s experience in Mexico City will likely inform their approach to similar high-altitude venues in the future, as they seek to enhance the durability and effectiveness of their power unit cooling solutions.