Piastri's McLaren debut cut short by fuel-systems issue in Barcelona test

Oscar Piastri's first outing in the 2026 McLaren MCL40 was significantly curtailed by a fuel-systems problem during the penultimate day of pre-season testing in Barcelona. The Australian managed only 48 laps, leaving the team with limited data as they grapple with the radically new car and power unit regulations for the season.

Why it matters:

Pre-season testing is a critical, time-sensitive period for teams to understand their new cars and identify reliability gremlins. Losing track time, especially for a driver's first experience with a completely new package, puts a team on the back foot in the race to solve fundamental issues before the competitive season begins. For McLaren, maximizing every lap is essential to close the gap to the front after a strong 2025 campaign.

The details:

• Piastri confirmed the team encountered "a few issues," with a fuel-systems problem being the primary fault that ended his running early on Thursday.
• The issue followed a delayed start to testing, with McLaren having missed the first day entirely to complete the build of the MCL40.
• Teammate Lando Norris, who drove on Wednesday, completed a more robust 76 laps and set the third-fastest time, indicating the car's potential when running smoothly.
• McLaren Technical Director of Performance, Mark Temple, stated the team brought the car in to fully strip and understand the problem, prioritizing a fix for the final day of running over continuing with a known fault.
• Temple added that the car's behavior was in line with simulations, with "nothing too unexpected" catching the drivers out, which is a positive baseline despite the reliability setback.

What's next:

The focus for McLaren on the final day in Barcelona will be twofold: executing a reliable fix for the fuel system to maximize Piastri's lap count and beginning the detailed work of tuning and understanding the new car's philosophy. With the 2026 cars representing a massive departure from previous years—featuring new engines, less downforce, and different energy management—every lap of data is precious. The team will aim to leave Spain with a resolved issue and a clearer direction for development before the official pre-season test in Bahrain.