F1 Testing Day 4: Aston Martin Set for Debut as Mercedes Impresses

The fourth and penultimate day of Formula 1's official pre-season shakedown at the Circuit de Barcelona-Catalunya is underway, with Aston Martin expected to finally debut its AMR26 car on track. The session follows a strong showing from Mercedes on Day 3, where rookie Kimi Antonelli and George Russell topped the unofficial timesheets.

Why it matters:

These closed-door tests provide the first genuine, on-track data points for the new 2026 cars, offering clues about the early competitive order and reliability. A team's ability to log significant mileage and performance during this limited running can set the tone for the opening races of the season, making every lap crucial for development and driver acclimatization.

The details:

• Aston Martin's Debut: After other teams began running earlier in the week, Aston Martin had specifically earmarked Day 4 for the AMR26's potential track debut, pending favorable weather conditions.
• Mercedes' Day 3 Pace: On Wednesday, Mercedes generated headlines as Kimi Antonelli reportedly set a fastest time of 1:17.362, edging teammate George Russell by two-tenths. The team also completed a high lap count, checking important boxes for both performance and reliability.
• McLaren's Running: Reigning world champion Lando Norris took the wheel for McLaren's first day of testing, ending the session third fastest while accumulating valuable mileage for the MCL38.
• Test Format: The FOM-arranged test is closed to the public, with each team permitted to run across three of the five total available days, forcing strategic decisions about when to deploy their cars and drivers.

What's next:

With only one day of testing remaining after today, teams will be pushing to complete their critical programs and finalize their understanding of the new cars before packing up for the season opener. All eyes will be on whether Aston Martin can get its planned running completed and if any other teams can challenge Mercedes' early pace before the shakedown concludes.