Mercedes-AMG Formula 1 drivers George Russell and Kimi Antonelli experienced significant and unexplained power unit issues during the Belgian Grand Prix, contributing to performance deficits and incidents. Team principal Toto Wolff described the problem as a "lack of energy" from the power unit, which affected all Mercedes-engined cars to varying degrees but impacted Russell more severely.
Qualifying Struggles
During qualifying, Russell suffered from a "mystery lack of energy" over a lap, which team officials estimated cost him between 0.2 and 0.25 seconds. This issue contributed to his qualifying deficit compared to his teammate. A similar problem was observed at McLaren, where Oscar Piastri faced an energy shortfall relative to Lando Norris. Both drivers experienced a reduction in energy on their opening lap, which played a role in Russell's first-lap collision with Lewis Hamilton and Max Verstappen overtaking Antonelli on the approach to Eau Rouge.
Race Day Complications
Wolff noted that a "new issue" emerged during the race, further complicating the team's strategy and performance. The fundamental complexity of the latest Formula 1 hybrid engines and their operating rules means that manufacturers and teams are still in a learning phase. Small variations in driving can disproportionately affect energy availability, a factor drivers find challenging.
Mclaren team principal Andrea Stella, a noted technical communicator, has frequently discussed the intricate nature of operating these power units. He explained that the system does not operate in a simple, predictable manner, but involves live calculations and forward-thinking by the control unit as the car progresses. This makes it difficult to understand the precise calculations being made during a lap.
Stella highlighted that these variations not only impact performance in power-limited sections and on straights but also affect braking points. Additional energy harvesting before braking can lead to a car approaching the braking zone at a slower speed, altering the driver's reference points. The unpredictable nature of these power unit variations, which can differ significantly from one lap to the next, makes them difficult for drivers to master. This complexity has also led to McLaren's frustration regarding the level of information they receive from Mercedes about the engine's operation, with Stella noting that the team is only now, midway through the season, acquiring the necessary tools to anticipate, optimize, and study these sensitivities.