Racing
© Spencer
Andrea Stella says Oscar Piastri’s two-tenths qualifying deficit to Lando Norris at Spa-Francorchamps had nothing to do with driving error and instead came from a small deviation in 2026 power-unit energy deployment on the run from Stavelot to the Bus Stop chicane.
The McLaren team principal said Piastri was “virtually” losing all of that gap on the final straight during the derating phase, when the cars are running out of electric energy and begin to slow down. Stella said the comparison between Norris and Piastri in Q3 showed the Australian was losing time through the final straight and Blanchimont “for reasons that have nothing to do with Oscar’s driving,” adding that he “could have been one to two tenths faster, just if the power unit had behaved as we anticipated.”
That made Spa a stark example of the problem teams are facing with the 2026 engines. Stella said these power units do not operate in a stable, open-loop way because a large part of their control comes from live calculations. Small changes in wind, grip and driver inputs can alter where energy is harvested and deployed, and the effects go beyond top speed. He said extra harvesting before a braking zone can leave a driver arriving “10km/h slower,” shifting braking references as well.
Stella said McLaren was still only getting the tools to simulate the Mercedes power unit before race weekends by race 10, underlining how far even a leading customer team is from fully predicting what the software will do. He said “most of the conversation this weekend has been about power unit and optimisation,” and argued the issue is not confined to customer teams because similar deviations can show up between works-team drivers too.
Williams team representative James Bowles offered a more specific theory for Mercedes’ edge. Speaking to Sky F1, Bowles said the works team appears to be “essentially, tricking the system so that they can use energy in more efficient places.” He said the trade-off is a lift late in the lap, and pointed to Spa data showing George Russell and Andrea Kimi Antonelli lifting in the final sector so they could use more energy on exit from the last corner and accelerate harder down the home straight.
Bowles said Williams, despite being a Mercedes customer, does not automatically have access to the same operational know-how. “We are a Mercedes customer team, but that doesn’t mean we can use the same things as them,” he said. “So we’re also giving our all behind the scenes, trying to find ways to operate the power unit in a similar way.”
The picture that emerges is that 2026 performance is being shaped not just by the power unit itself, but by who best understands its software control and the timing of recovery and deployment. Spa exposed that especially clearly because straight-line performance could swing on tiny variations that drivers may not even feel in real time.
That is what has turned a technical challenge into a wider racing concern. Mercedes driver George Russell said after qualifying that “my whole focus for the last 36 hours has been on straightline speed. It hasn’t been focusing on the set-up, the tyres or anything, because we're all trying to solve what is going on.” Piastri was even blunter about the direction of travel: “When you've got qualifying decided by computers behaving or misbehaving, it's a pretty crap way of going racing.”