The fourth day of the F1 2026 shakedown in Barcelona saw Mercedes continue its strong performance, accumulating valuable mileage. Aston Martin finally made its track debut, a key moment for the team as they prepare for the new season. These shakedown sessions are vital for teams to test new car designs and engine configurations ahead of the upcoming races.

George Russell and Andrea Kimi Antonelli shared driving duties for Mercedes, focusing on long runs and various setups. The goal is to optimize the car's performance and reliability. Meanwhile, McLaren experienced an early end to their day due to technical issues, a setback that teams will aim to resolve quickly. These initial tests will shape the competitive order.

The shakedown is a closed-door event, so detailed lap times and specific performance data are scarce. However, the early signs suggest that Mercedes is in a strong position. Aston Martin's late appearance raises anticipation for their progress. All teams are working to refine their cars before official testing.

This early running in Barcelona is a crucial part of the development cycle. Teams use these sessions to iron out issues. The teams are working on new engine regulations and car designs for the 2026 season. These tests help them gather data and fine-tune their strategies for the upcoming races, starting with the first Grand Prix.