The Formula 1 weekend at Spa-Francorchamps underlined a growing frustration with the 2026 power units: drivers can lose qualifying time because of energy-management behaviour they cannot fully control.
Spa is an especially demanding venue for the system. Its long straights and fast corners offer few opportunities to harvest energy, leaving drivers reliant on the internal combustion engine through the second sector. That output is around 540 horsepower, below the approximately 620 horsepower produced by Mecachrome engines in Formula 2.
The result is a circuit where small changes in energy deployment can carry a significant effect down the lap. McLaren team principal Andrea Stella explained on Saturday evening that the new power units include self-learning elements. They can learn from lap to lap, and even during a lap, to anticipate energy-management requirements.
Stella also stressed that the system is highly sensitive. Minor variations in driver input can create a major difference later in the lap, while changes in grip and wind direction can produce a similar effect without being under the driver's control.
That appeared to affect Oscar Piastri in qualifying. Despite both McLaren power units running identical settings, he lost substantial time to team-mate Lando Norris. Stella suggested George Russell had encountered a comparable issue, having been unable to explain the time he lost to Kimi Antonelli on the straights. The wider context of Spa's power-unit demands has also featured in recent analysis of Mercedes' straight-line advantage.
Piastri made his frustration clear when asked how it felt to be caught out by his own power unit.
“It sucks. I can't really say it any other way than that...”
The Australian said the problem was not unique to him or McLaren. He argued that qualifying grids should not be decided by computers “behaving or misbehaving”, particularly when a driver can feel level with a team-mate in the corners yet finish two tenths behind at the end of the lap.
Norris shared that concern. Although he benefited at Spa, he said power-unit problems had affected him throughout the season and that this was the first weekend when he felt competitive on the straights.
“There are certain things within your control and a lot of things, way too many things, that are out of your control,” Norris said, adding that qualifying can become a matter of hoping the power unit performs as expected.
Piastri does not expect the planned shift in the balance between combustion and electrical power to solve these specific problems. He said the issue is rooted in calibration and the way the engines learn, although he expects performance to improve as manufacturers understand the systems better.
For now, Spa has sharpened a difficult question for the 2026 era: how much of a qualifying lap should be decided by the driver, and how much by an unpredictable power unit?
Simone Scanu
He’s a software engineer with a deep passion for Formula 1 and motorsport. He co-founded Formula Live Pulse to make live telemetry and race insights accessible, visual, and easy to follow.
Piastri and Norris frustrated by Power Unit unpredictability: "It sucks" | Formula Live Pulse
