On the fourth day of secret testing in Montmeló, Mercedes once again showed strength through pace, mileage, and reliability. In a week focused on adapting to the 2026 regulations, the German team leads the benchmarks while the rest of the field continues validating new components.
The fourth day of closed-door Formula 1 2026 testing in Barcelona kept the spotlight on adaptation to the new technical regulations and, from a Mercedes-Benz perspective, once again delivered clear signals about the German team’s working method. With stable operation from the W17 and a well-structured running plan, the team prioritized data gathering and system validation over outright performance, in a week that remains exploratory for the entire grid.
Private testing in Montmeló is being held under a restrictive format. Each team can choose only three days of activity within a five-day window, which forces precise planning for every on-track outing. In that context, Mercedes managed to complete a high volume of laps without lengthy interruptions, a key point at a stage where reliability is just as important as speed.
The team’s work was built around long runs, race simulations, and tests with different aerodynamic configurations and tire compounds. Beyond the lap times recorded, the priority was evaluating the car’s overall behavior, the response of the power unit, and the integration of systems under the rules that will come into force in 2026.
While Mercedes progressed smoothly, other teams experienced more uneven days. Ferrari and Red Bull alternated track presence in the previous sessions, adjusting their programs based on changing conditions and accumulated mileage. The closed nature of the test limited the information available externally, meaning many conclusions are drawn from movements and lap counts.
Weather also played a role in the development of the fourth day. Some sessions were affected by rain or unrepresentative temperatures, forcing teams to modify plans on the fly. In that scenario, Mercedes’ continuity stood out as one of the clearest takeaways of the week, with a program that saw no major disruptions.
Adapting to the 2026 regulations represents a deep challenge for all teams. The changes span aerodynamics, power units, and new approaches to efficiency and energy management. Within that framework, logging miles without major failures allows teams to build a solid foundation for the next stages.
With an eye on the official tests and the start of the championship, Mercedes wraps up this phase in Barcelona with a broad set of data. The methodical approach and on-track reliability shown allow the team to move into the next preparation phase with clear benchmarks ahead of the 2026 season opener.