Carlos Sainz completes Williams FW48 seat fit as team prepares for 2026 season

Carlos Sainz has completed his seat fitting in the Williams FW48, a key milestone as the team prepares for its delayed start to 2026 pre-season testing. Williams is the only team to miss this week's collective shakedown in Barcelona, a decision Team Principal James Vowles described as "incredibly painful" but necessary to ensure the team is properly prepared for the season ahead.

Why it matters:

Williams is betting its 2026 campaign on a radically new car built around the sport's sweeping new technical regulations. Missing the first official test is a significant gamble, underscoring the team's aggressive development push and the pressure to deliver a competitive package from the outset. Sainz's integration is a critical piece of this puzzle as the team aims to capitalize on the new rules to move up the grid.

The details:

• Team Principal James Vowles confirmed the team will join testing at the second session in Bahrain next month, having skipped the Barcelona shakedown due to "delays in the FW48 programme."
• Vowles stated the delays resulted from a push to maximize performance under the 2026 rules, which introduce 50% electrification, sustainable fuels, and active aerodynamics.
• While the team could have attended the Barcelona test, Vowles argued it would have compromised the availability of spare parts for the early races, referencing the team's past struggle with a single chassis at the 2024 Australian Grand Prix.
• Sainz's seat fit follows similar milestones by other drivers, including Valtteri Bottas at Cadillac in December and Kimi Antonelli at Mercedes earlier this month.

What's next:

All focus now shifts to Bahrain, where Williams must hit the ground running. The team's performance in the two tests there will be the first real indicator of whether its high-risk strategy of forgoing Barcelona has paid off. For Sainz, entering his second season with the team, a reliable and competitive FW48 is essential to build on the podium finishes he achieved in 2025 and establish Williams as a consistent points contender.