Mercedes makes full power unit change during Bahrain test

Mercedes was forced to undertake a complete power unit change on Kimi Antonelli's car during the second day of pre-season testing in Bahrain, costing the team and its rookie driver valuable track time. This follows a suspension issue that limited the team to just 85 laps on the opening day, compounding a difficult start to their testing program.

Why it matters:

Reliability is a cornerstone of pre-season testing, where teams gather critical data and drivers build confidence with the new car. Losing significant running, especially for a rookie like Antonelli who needs every possible lap to prepare for his debut season, represents a substantial setback. For Mercedes, which is aiming to close the gap to the front, any technical gremlins that disrupt their data collection and development schedule are a major concern.

The details:

• The issue was discovered with the power unit in Antonelli's car on Thursday morning, prompting an investigation by the team.
• Mercedes engineers decided a full power unit replacement was necessary, ruling the Italian driver out of any running before the lunch break.
• Antonelli had failed to complete a single lap on Thursday before the issue arose.
• This compounds problems from Wednesday's first day of testing, where a separate suspension problem limited the team's total lap count to 85.

What's next:

The focus for Mercedes will be on diagnosing the root cause of the power unit issue to prevent a recurrence. The team will be eager to maximize running in the remaining test sessions to recover the lost data and give Antonelli more seat time. While pre-season problems are not uncommon, their frequency and severity at this early stage will be a worry for a team with championship aspirations, putting pressure on their reliability preparations for the opening race.