Mercedes hits second Bahrain test snag with Antonelli power unit failure

Mercedes' pre-season testing in Bahrain has been disrupted for a second consecutive day, with Andrea Kimi Antonelli's W17 stopping on track after just three laps due to a power unit issue. The setback compounds a suspension problem that limited his running on Wednesday and comes as rival Red Bull also faced a significant delay in its garage.

Why it matters:

Reliability is a critical benchmark in testing, and consecutive mechanical issues for Mercedes raise questions about the team's winter preparation just days before the season opener. For Antonelli, the lost track time is a significant blow to his acclimatization in a car he is tipped to race full-time in the near future, potentially affecting both immediate performance data and long-term development plans.

The details:

• Antonelli's car suffered the failure early in the Thursday morning session, requiring a full power unit replacement to attempt a return to the track in the afternoon.
• This follows a suspension issue on Wednesday that restricted him to only 30 laps, while teammate George Russell managed 56 in the morning.
• The team may now adjust its run plan for Thursday or Friday to rebalance track time between its drivers, skewing the valuable testing data.
• Red Bull's parallel delay: The reigning champions also lost track time, with Isack Hadjar's running delayed by two hours due to what the team described as a "routine issue during the car build."
• Regulatory backdrop: The reliability concerns emerge amid a technical dispute, where rival manufacturers are challenging Mercedes' interpretation of engine compression ratio regulations—a row team principal Toto Wolff has warned could leave Mercedes "screwed" if the FIA sides against them.

What's next:

Mercedes' immediate focus is repairing the car to maximize the remaining test days, with Russell scheduled for the afternoon session. The team must quickly diagnose the root cause of the power unit failure to prevent it from becoming a recurring theme. All eyes will be on whether the W17 can complete consistent long runs, as the on-track issues add another layer of intrigue to the ongoing off-track engine regulation debates.