McLaren broke an invisible barrier by claiming successive constructors Championships in 2024 and 2025. Prior to the Woking team’s title triumphs, the widespread belief in Formula 1 was that customer teams would always have an inherent ceiling.
This motivated Aston Martin to abandon Mercedes power and partner with Honda for 2026. A similar conclusion pushed Red Bull to develop their own powertrains department for these regulations.
Of course, McLaren have demonstrated that being a customer team does not make Championships unattainable.
Still, there are areas that customers must work around that manufacturers do not. Focusing on McLaren’s MCL40, there has been one main focus in recent weeks.
McLaren aim to optimise Mercedes power unit
One of the main talking points in Bahrain testing was the top speeds teams were achieving. For obvious reasons, this was used as a way to measure peak engine performance and horsepower.
However, in modern F1, arguably more important than an engine’s maximum horsepower is its efficiency.
The electric component of these new hybrid engines will be critical in the coming years. Power units that are more efficient at harvesting and redeploying energy will have more power to utilise across an entire lap.
This means the most powerful engine will not necessarily be the best overall in 2026.
Because of this, McLaren are working vigorously to understand their power unit. As a customer team, they are less familiar with Mercedes’ latest powertrain than the German manufacturers themselves.
Moreover, Mercedes had the luxury of making an engine to compliment their aerodynamic philosophy. McLaren, meanwhile, were made to work around the components provided to them by the Brackley-based outfit.
Heading into this weekend’s Australian GP, McLaren identify that optimising their engine is the first order of business.
Chief Technical Officer and Designer Rob Marshall has explained the situation:
“We have spent much of our testing programme exploring the performance and capability of our car, with every lap providing valuable further understanding of the MCL40..
“Power unit exploitation has been a very intense focus, with multiple areas to get right on the hybrid side – such as when to recover energy, and when to deploy across the different scenarios a race weekend provides.
“This has required many laps, but we are confident in our learnings and will continue to explore areas for further exploitation in performance.”
Establishing the pecking order
Since the conclusion of pre-season testing, predicting the fastest and slowest teams has been the main talking point in F1 media.
In typical fashion, the front-runners did not show their hand in testing. This means the Australian GP weekend will be the first accurate representation of where the field stands.
Generally speaking, McLaren are seen as being slightly behind Mercedes and Ferrari – though still comfortably among the top teams.
Understandably, CTO Rob Marshall has no interest in declaring McLaren as the favourites for 2026. Instead, the 57-year-old points to the other teams he expects to accompany the papaya squad at the front of the field.
Moreover, Marshall reiterates the importance of understanding the Mercedes power unit:
“To be in condition to compete at the front and challenge for the race victory, you will need to have done a very good job on managing the power unit. This is something you need to be on top of.
“Overall, this will be a fascinating season. The development race will be intense, and it has been harder than ever to judge the pecking order in testing.
“I think we are in the leading group alongside some very strong competition – such as Ferrari, Mercedes, and Red Bull. But there are lots of elements throughout the 2026 season that could provide some surprises.
“We’re looking forward to getting the season underway.”